The China-US security relationship is complicated and confusing,with contest and cooperation intertwined with each other under a“neither friend,nor enemy”framework.Nonetheless,nonproliferation cooperation has always been a bright spot in China-US security cooperation for over more than a decade.China-US cooperation has proven to be very fruitful evident from the Six-Party Talks to the Iran Nuclear Treaty and from the Nuclear Security Summit to export control.In April,when the heads of state of China and the U.S.met at Mar-a-Lago,the North Korea nuclear issue as well as the trade and economic issue were the two core themes for their talks,which reflected the importance of nonproliferation in China-US relations.But in recent years,the international nonproliferation situation is undergoing many changes,for example,the Iran nuclear issue and the nuclear security issue that once prompted China and the U.S.to engage in close cooperation is cooling off,while other relevant issues such as missile defense and admission standards of Nuclear Suppliers Group(NSG),on which China and the U.S.conflict with each other,are becoming more pronounced.Under these new circumstances,it has become a concern whether nonproliferation will continue to be a bright spot in China-US cooperation.

在饮食上，应合理调整蛋白质、脂肪、糖的比例，适当食用含维生素多的水果、蔬菜。加工上，应多采用煮、炖、熬、蒸等方法。每日应保证一定数量的优质蛋白质的摄入，可食瘦肉、牛奶、蛋、鱼等食品以及各种大豆制品。每日膳食中蔬菜及水果不能缺少，保证维生素及无机盐、微量元素的供给，提供膳食纤维。还可适度应用人参、黄芪、桂圆、山药等有抗衰老作用的药物、食物，制成药膳食用。对于年老的患者，原本身体虚弱，营养不够，不需忌口太严，以顺其自然为宜。

Chinese and US scholars are not in consensus on this issue.Some of them　are　ratheroptimistic,believing　thatalthough　the　China-US relationship is entering a new pattern of“No.One vs.No.Two”,the existing common strategic interests of both countries are reducing,so nonproliferation will remain an issue of common concern for the two countries,which will lead them to strengthen their strategic coordination.Other scholars are rather pessimistic,deeming that there is a great disparity of shared interests between China and the United States in regard to nonproliferation,as China is happy to see the U.S.tired and exhausted from intervening in international affairs while playing the role of mediator.As a result,there is no ground for common interests between the two countries to strengthen their cooperation.1Ref.Yuan Peng,“Guanyu goujian zhongmei xinxing daguoguanxi de zhanlue sikao[Strategic reflections on the construction of the new yype of great power relationship between China and the United States]”,Xiandai guoji guanxi[Contemporary International Relations],No.5,(2012);Lora Saalman(US),“Shixi zhongmei hebukuosan hezuo[Probing into China-US nuclear nonproliferation cooperation]”,Zhongguo guoji zhanlue pinglun[China International Strategic Review],(2012):303-318;Shen Dingli,“Shaping Effective Cooperation on Nuclear Nonproliferation For Conference on Strategic Cooperation Between the United States and China,”April 30,2014,accessed January 10,2017,http://d3qi0qp55mx5f5.cloudfront.net/cpost/i/docs/Shen_Policy_Memo.pdf;Evan　S.Medeiros,ReluctantRestraint:The Evolution of China’s Nonproliferation Policies and Practices,1980-2004,(Stanford University Press,2007);Li Shaojun,“Zhongguo yu hebukuosan tizhi[China and the nonproliferation regime]”,Shijie jingji yu zhengzhi[World Economics and Politics],No.10(2001):60-65;Wang Jun,“Lengzhanhou zhongguo bukuosan zhengce de zhuanbian jiqi yuanyin fenxi[The change of China’s nonproliferation policy in the wake of the Cold War and analysis of its causes]”,Taipingyang xuebao[Pacific Journal],No.4(2002):61-71;Zhu Liqun,Gary Boch(US)and Lu Jing ed.,Guoji fangkuosan tixi:Zhongguo yu Meiguo[The international nonproliferation system:China and the United States],Shijie zhishi chubanshe[World Affairs Press],First Edition,December,2011;Fan Jishe,“Zhonguo hebukuosan de silu yu fangfa[China’s thinking and method in nuclear nonproliferation]”,in Li Bin ed.,Lijie zhongguo hesiwei[Understanding China’s nuclear thinking],Shehui Kexue Wenxian Chubanshe[Social Science Literature Press],first edition,January,2016;Tian Jingmei,Guoji hebukuosan jizhi[International nuclear nonproliferation regime],Zhogguo yuanzineng chubanshe[China Atomic Energy Press],2016;Liu Xinghua,“Guoji hebukosan jizhi zhong de meiguo yu zhongguo”[The United States and China in the international nuclear nonproliferation regime],in Li Genxin ed.,2006:Gaoji junbei kongzhi yu caijun baogao[Report on international arms control and disarmament—2006](Shijie zhishi chubanshe[World Affairs Press],first edition,May,2006),214-222;Teng Jianqun,“Zhongmei guanxi zhong de fangkuosan yu fankuosan yinsu 2006 Guoji junbei kongzhi yu caijun baogao[The nonproliferation and anti-proliferation factors in China-US relationship]”,in Li Genxin ed.,2006:Gaoji junbei kongzhi yu caijun baogao[Report on international arms control and disarmament—2006](Shijie zhishi chubanshe[World Affairs Press],first edition,May 2007),178-189.This paper is intended to review China-US nonproliferation since 9/11,sum up the basic patterns of cooperation between the two countries and analyze the reasons why nonproliferation could become a bright spot in the China-US relationship,on which to look into the future challenges and opportunities that may be confronted.This paper holds that the internal and external environment for China-US nonproliferation cooperation is undergoing profound changes,as some of the effective cooperation models over the past decade are likely to fail under these new circumstances.But we must also see the opportunities and hope brought about by such changes in this new situation.China and the U.S.should act in accordance with the changes,actively innovating the nonproliferation cooperation model,seeking new growth points and striving to make it a foundation for building a new type of great power relations.

Nonproliferation：ABright Spot in China-US Cooperation

Historically,the　China-US　relationship　in　nonproliferation　has undergone drastic changes.In the early 1960s,the U.S.concluded the Partial Nuclear Test Ban Treaty with the U.K.and Soviet Union,targeting China who was engaged in developing nuclear weapons,which was dismissed by Chairman Mao Zedong as the“treaty of the three.”China was also critical about the Nonproliferation Treaty(NPT)led by the U.S.and Soviet Union,believing it to be a tool of the nuclear powers to protect their nuclear monopoly.In the 1980s,when China and the U.S.began cooperation in nonproliferation,China changed its attitude toward the international nonproliferation regime and joined such nonproliferation organizations as the International Atomic Energy Agency(IAEA),while the U.S.moderately relaxed export restrictions on China.In the 1990s,nonproliferation became a major cause for conflict and Friction between China and the United States,as seen in the case of the Yinhe incident.Meanwhile,　China　was　further　integrated　into　the　international nonproliferation regime whiling engaging in a series of cooperation efforts with the U.S.on international and regional nonproliferation issues.1Wang Qiaorong,“Zhongmei guanxi zhong de fangkuosan wenti yanjiu[Studying the issue of nonproliferation in China-US relationship]”,Zhonggong dangshi yanjiu[CPC history research],No.2(2011):76-84.In the wake of 9/11,nonproliferation cooperation has become an important platform for China-US cooperation.In practice,the two sides have gradually formed relatively stable cooperation models on different levels.

I.In the domain of building an international nonproliferation regime,the U.S.and China are in a relationship as both advocate and major participants as well as builders.The U.S.,as the chief architect of the existing international nonproliferation regime,has played the leading role with a relatively strong ability to create and promote issues for discussion.Though China is a latecomer in the international nonproliferation regime,it has manifested a strong will for cooperation and an even stronger ability for learning its international synergy since having become a major participant and builder of the international nonproliferation regime.In the 1990s,China and the U.S.jointly promoted the indefinite extension of the NPT and negotiations on the Comprehensive Nuclear-Test-Ban Treaty(CTBT),hand in hand laying a solid foundation for the international nonproliferation regime.Since the beginning of the 21st century,China and the U.S.have made more cooperation achievements in enhancing the international nonproliferation regime,as outlined below.

根据表1、表2可知，无论常量元素还是微量元素，大多都发生了富集现象，而元素的来源与地表水及地下水有很大关系。化学溶蚀对母岩化学成分的改变很大，CaCO3、MgCO3溶解后被水流带走，剩余的难溶物质开始富集，Al2O3、Fe2O3等在母岩中的含量还不足1%，却成为难溶堆积物的主要成分。这也说明要形成一定厚度的残余堆积物，需要溶蚀更大厚度的母岩。碳酸盐岩的岩溶作用不断将母岩中的可溶性成分溶解并随水带走，剩下的部分是难溶物质富集起来，所以 Si、Al、Fe 的比例逐渐增多,Ca、Mg 等盐基物质则逐渐减少。

高校应针对本科生考研与就业的抉择，科学定位应用型和学术型人才的分类培养目标，建立分类人才培养模式。高校目前普遍存在着重考研引导轻考研指导的弊病，且对考研学生缺乏系统的培养体系，无法满足当前低年级就启动考研行为的学生需求，直接造成了学生“考研与本科教学之间的矛盾”。﹝3﹞因此，积极探索考研和就业的分类人才培养模式，弹性设置课程体系，灵活执行教学计划，将有利于帮助本科生尽早定位，缓解本科生考研学习和专业学习的矛盾，体现“因材施教”的原则,有效地避免考研对本科教育教学的冲击。

A.As seen in the enhanced building of an international nuclear security regime.The international nonproliferation regimes that existed in the past were mainly confined to sovereign states,which failed to regulate proliferation issues related to non-state actors including terrorist groups.With the joint promotion and support of China and the U.S.,the international community has formulated a series of international rules to enhance nuclear security,such as the International Convention for the Suppression of Acts of Nuclear Terrorism that concluded in 2005,the UN Security Council Resolution 1540 that is intended to enhance export controls on concerned countries and fight against proliferation issues related to non-state actors,and the UN Security Council Resolution 1373 and Resolution 1624,which includes measures for anti-nuclear terrorism.1Gareth Evans,Tanya Ogilvie-White,and Ramesh Thakur,Nuclear Weapons:The State of Play 2015,Australian National University,2015,173-174. In 2006,the U.S.and Russia proposed the Global Initiative to Combat Nuclear Terrorism(GICNT),and China joined as an original-member state.The China’s top leader participated in the Nuclear Security Summit launched by the United States,jointly promoting the improvement of global security measures for nuclear materials.

A.Cooperation in nonproliferation export control.Export control is an important measure to prevent proliferation of WMDs and their means of delivery.China has participated in the Container Safety Initiative and the Megaports Initiative initiated by the U.S.,and has engaged in extensive cooperation with the U.S.on export control by handling individual cases and supervising law enforcement.

II.In coping with regional nuclear hotspots,China and the U.S.seek common　ground　whilereserving　theirdifferences,and　engagein complementary cooperation,playing the roles,to some extent,of“good cop”and“bad cop”.In regard to cooperation strategies to cope with regional nonproliferation issues,China and the U.S.have given full play to their comparative advantages:as the largest developed country,the U.S.has the most expansive alliance network in the world,and as the leader of NATO and its Asia-Pacific allies,it has relatively great discourse power in the West;while China is the largest developing country with unique influence among the BRICS countries and the developing countries in Asia,Africa　and　Latin　America.When　dealing　with　regional nonproliferation issues,China has often played the role of middleman or mediator between the Western countries and the regional hotspot countries.When opposition is strong or negotiations can hardly make progress,it is often China that will act as a go-between to keep negotiations going.Therefore,in nonproliferation cooperation,China and the U.S.can make greater achievements together than if they work separately,which can be seen in such cases as the North Korea nuclear issue,the Iran nuclear issue and the Syrian chemical weapons issue,as outlined below.

A.Jointly coping with the North Korea nuclear issue.When the North Korea nuclear issue came up again in 2002,at the request of the U.S.,China acted as the honest middleman between the U.S.and DPRK by hosting the Six-Party Talks,providing not only a platform for US-North Korea dialogue,but also a multilateral guarantee to ensure effective implementation of their bilateral agreements.Since the Six-Party Talks came to a halt in December of 2008,China and the U.S.have essentially maintained the same position of denying DPRK the status as a Nuclear Weapon　State,opposing　itsnucleartestsand　preventing　itfrom proliferating nuclear weapons.

B.Promoting the conclusion of the Iran nuclear agreement.When the Iran nuclear issue was submitted to the UN Security Council in 2006,China,the U.S.and Russia became involved,forming the P5+1 framework on the issue.With the involvement of China and the U.S.,the six countries have proposed various solutions to resolve the Iran nuclear issue.They reached a framework agreement in April of 2015,which has limited the Iranian nuclear program for 10 to 15 years to come.In this process,China has played an important role,not only mediating and encouraging dialogue between the U.S.and Iran,but also proposing solutions to key issues that beset the concerned parties and halted the negotiation process.For instance,the negotiations on the Iran nuclear issue were once at a deadlock because of the Arak heavy water reactor,when China proposed plans to transform the heavy water reactor,paving the way for the final conclusion of the agreement.

C.Successfully resolving the Syrian chemical weapon issue.In 2013,the Syrian insurgents accused the Syrian government of using chemical weapons on civilians and inflicting great casualties.The U.S.President Obamasoughtauthorizationfrom　Congresstoengageinmilitary intervention,creating a tense situation.To defuse the crisis,Russia proposed that the Syrian chemical weapons be put under international supervision and dismantled progressively,which was welcomed by both the U.S.and Syria as well as authorized by the UN.China and the U.S.,together with other countries,participated in disposing the Syrian chemical weapons.Chinese and Russian warships were responsible for escorting the ship that was transporting the chemical weapons,while the U.S.was responsible for destroying them out at sea.This action has indicated that although China and the U.S.have failed to reach consensus on certain regional issues or sometimes have sharp conflict against one another,they can still seek common ground to achieve concrete results while reserving their differences on issues relating to nonproliferation.

III.In bilateral cooperation,training programs and coordination in nonproliferation between China and the U.S.have increased,forming a close-knit network for exchanges and cooperation.Like in other fields,there is a need for the Chinese nonproliferation regime to synchronize with those of the international community and the need for China to learn from the experiences of the developed countries,with the U.S.providing perhaps the most significant lessons for China to learn from.Meanwhile,the U.S.needs China’s support to ensure the safety of its supply chain and to prevent its potential rivals from obtaining sensitive materials from China that are needed to make Weapons of Mass Destruction(WMDs).The bilateral cooperation between China and the U.S.concentrates on two aspects outlined below.

相对于CAD技术在中国三十多年的发展，BIM技术在中国的应用与发展不过是“才露尖尖角”，虽然我国从2009年开始就在政策层面持续大力推动BIM技术应用，但是，由于VR等高新技术、智慧建筑等朝阳行业的出现与快速发展，对BIM技术的应用提出了更多新要求。

B.As seen in safeguarding the international nonproliferation regime.Within the UN’s framework,China and the U.S.have jointly promoted the international community to forge consensus on nonproliferation.In September of 2009,under the promotion of the U.S.,the UN Security Council convened for the first summit on nuclear nonproliferation and nuclear disarmament.The summit was presided over by President Obama,with Chinese President Hu Jintao participating and addressing the summit,which provided political dynamics for advancing cooperation in nuclear disarmament and nuclear security.Under the NPT framework,China and the U.S.have boosted the confidence of the international community in nonproliferation by establishing the five recognized Nuclear Weapons States.In regard to the informal nonproliferation regimes,China,with American support,joined the Nuclear Suppliers Group(NSG)in 2004.China has aligned with the purpose and objectives of the Proliferation Security Initiative,but did not join because China has remained doubtful about the possibility that it would intercept beyond the scope of international law.Nonetheless,as American officials have revealed,China and the U.S.have cooperated on certain cases.1Shirley A.Kan,China and Proliferation of Weapons of Mass Destruction and Missiles:Policy Issues,January 5,2015,53,accessed on January 1,2017,https://fas.org/sgp/crs/nuke/RL31555.pdf.

按照私民社会理论，在我国城市住宅小区内部，作为国家权力作用场域的公共空间和公共领域基本不存在。那么，在私人构成的集体空间或私民社会中，国家的进入和控制是否具有正当性?建筑物的产权和公共部位的物权或者所有权，能否延伸出小区内部集体事务的治理权?

B.Cooperation on nuclear security.China National Atomic Energy Agency,China Nuclear Safety Agency and the Nuclear Power Division underthe　Energy　Bureau　ofChina　Developmentand　Reform Commission　have　their　separate　communication　channels　and cooperation programs with the U.S.Department of Energy.China and the U.S.have also effectively cooperated in providing nuclear security for big events,such as when the U.S.government sent a nuclear emergency support team to provide security assistance for the 2008 Olympic Games.Of late,China-US nuclear security cooperation has been further upgraded.In February of 2016,several government departments of China and the U.S.held their first nuclear security dialogue.During the 4th Nuclear Security Summit,President Xi Jinping together with President Obama issued the Joint Statement on Nuclear Security Cooperation between China and the United States,pledging to strengthen cooperation in reforming high concentration reactors,providing nuclear safety training,combating nuclear smuggling,and safekeeping radioactive sources.

Motivation and Impact

C.It has improved the external environment for China-US economic exchanges and trade.Nonproliferation has been closely related to China-US economic and trade cooperation.First,when exporting high-tech items to China,the U.S.is concerned that they will be used for military purposes or by military consumers,affecting the smooth high-tech trade between China and the United States.Second,the U.S.often imposes sanctions on Chinese companies for exporting so-called“sensitive items”to a third country by invoking domestic laws and prohibiting them from trading with the United States.Through export control cooperation,China and　the　U.S.have　made　someprogressin　removing　the　two aforementioned obstacles.First of all,China and the U.S.have cooperated in export control to the ultimate extent,which has eliminated the uncertainties of the U.S.that the items they export to China would be diverted to other purposes,and have greatly facilitated bilateral high-tech trade.In 2004,China and the U.S.reached an agreement on end-user verification,with China permitting the U.S.to perform on-site end-user verification on high-tech products exported to China.In 2009,the commerce departments of China and the U.S.concluded an agreement that granted access to the verified end users.According to this agreement,American exporters can export specific dual-use items to Chinese enterprises authorized as the verified end user without applying for an export permit,which has greatly lowered trading costs and stabilized trading　expectations.　Secondly,　Chinese　export　enterprises　have strengthened their internal control mechanisms,which has helped reduce the probability of being punished.

在粒子群算法中,由粒子的速度更新式(18)可知,惯性权重ω决定了粒子对当前速度的继承程度。如果惯性权重ω取值较小,则对当前速度继承程度较小,粒子的局部搜索能力强,但是容易陷入局部最优;若惯性权重取值较大,则对当前速度继承程度较大,粒子的全局搜索能力强,但是不利于算法局部的寻优能力。所以对于惯性权重ω的最佳的选取是前期取较大值,保证粒子有较强的全局搜索能力,后期为了能够利于粒子的精细搜索,惯性权重ω取较小值。为此,改进惯性权重ω为自适应惯性权重,如式(20)所示:

B.Both China and the U.S.believe nonproliferation conforms to their fundamental interests.For the U.S.,their fundamental objective in the wake of the Cold War is to maintain its global hegemony.American scholars hold that nonproliferation together with containing their rivals and facilitating economic integration constitute three great strategies to safeguard American hegemony.1Francis J.Gavin,“Strategies of Inhibition,U.S.Grand Strategy,the Nuclear Revolution,and Nonproliferation,”International Security,Vol.40,No.1(Summer 2015):9-46.At the beginning of the 21st century,the U.S.was hesitant about which should be its principal task—containing such major powers as Russia and China or combating terrorism and proliferation.But 9/11 has made the U.S.aware that nonproliferation and counter terrorism are the most severe challenges it faces.The Bush Jr.administration released the National Strategy to Combat Weapons of Mass Destruction in 2002,claiming that“weapons of mass destruction falling into the hands of American enemies or terrorists are one of the most severe threats facing American national security.”2National Strategy to Combat Weapons of Mass Destruction,December 2002,1,accessed on March 4,2016,http://www.state.gov/documents/organization/16092.pdf.The Obama administration pointed out in the Nuclear Posture Review—2010 that preventing nuclear terrorism and nuclear proliferation is the“most urgent task.”3Nuclear Posture Review,April 2010,v,accessed on March 4,2016,http://www.defense.gov/News/Special-Reports/NPR.Why has the United States attached so much importance to the issue of nonproliferation?First,the more nuclear power countries and non-state actors,the more likely the United States is to get involved in a nuclear war,and bigger the risk of nuclear attack on the United States.Second,other nuclear power countries may deter the U.S.and pursue a policy of area-denial,which would impede the U.S.power and limit the U.S.military action of freedom spreading.4The US Department of Defense,Department of Defense Strategy for Countering Weapons of Mass Destruction,June 2014,Introduction,accessed on January 2,2017,http://archive.defense.gov/pubs/DoD_Strategy_for_Countering_Weapons_of_Mass_Destruction_dated_June_2014.pdfThird,the U.S.alliance network would likely be impacted,as it will be hard to control its allies if they attained nuclear capability,and the credibility of American security and protection would be weakened if its rivals attained nuclear capability.5Francis J.Gavin,“Strategies of Inhibition,U.S.Grand Strategy,the Nuclear Revolution,and Nonproliferation,”International Security,Vol.40,No.1(Summer 2015):9-46.The United States needs to gain international support for nonproliferation,with three main appeals to China:one,deal with nuclear crises and prevent nuclear proliferation by using China’s close relations with North Korea,Iran and Pakistan;two,urge China to strengthen export control to prevent opportunities for other countries or non-state actors to seek WMDs;and three,urge China to actively promote American nonproliferation initiatives to enhance American dominance in arms control.

I.The motivation for China-US nonproliferation cooperation.We have to examine both the subjective and objective causes for China and the U.S.to strengthen their nonproliferation cooperation.

II.The impact of China-US nonproliferation cooperation.Nonproliferation cooperation has become an important tie in the China-US relationship over the past decade,as it has lasted for a long time,touched a wide range of issues,involved many departments and yielded substantial results.

针对鲜食玉米单产低、集中上市滞销、品质下降、销售难、价格低等问题，在品种选择上以市场为导向，满足城镇居民求新、讲营养、重保健的需求，更新更换品种；为进一步开拓市场，完善鲜食玉米栽培技术，促进城郊农业结构调整，增加农民收入，在技术上，以促早栽培技术为突破口，解决了鲜食玉米集中上市产品滞销而影响品质的问题；通过实践摸索总结示范推广了以鲜食玉米为主茬作物的多种高效模式，对促进城郊型农业结构调整发展城郊型农业，为实现农业增效，农民增收起到了很好的作用。

For China,the fundamental strategic objective established since the reforms and opening-up began is to seek development.The concrete substance of this objective has kept up with the times and China continuous to be enriched.In accordance with both internal and external affairs,the 16th National Congress of the Communist Party of China(CPC)held in 2002 made an important decision claiming that the first 20 years of the 21st century would be a period of important strategic opportunities,calling the whole nation to grasp this opportunity and build a prosperous,well-rounded society.Since then,safeguarding and extending this period of important strategic opportunities has been the core objective of China’s diplomacy.Proliferation of WMDs poses major threats to the realization of China’s strategic objectives in several ways:first,the emerging nuclear weapons in Asian and around China’s neighborhood will pose a potential military threat to China;second,the proliferation of WMDs will easily cause tension and destroy regional peace;and lastly,nuclear tests will pose severe threats to environmental security.Strengthening China-US nonproliferation cooperation will serve the goal of maintaining the period of important strategic opportunities for China in two ways:first,it is conducive to enhancing mutual understanding and trust between China and the U.S.,expanding common interests and stabilizing the overall situation of bilateral relations;and second,it may help manage and control hot issues that interrupt international and regional peace and stability as well as prevent them from threatening China’s security and interrupting its development.Based on this,in 2002,China proposed to make“the issue ofnonproliferation　a　positive　factorthatpromotesthe　healthy development of the China-US relationship and a bright spot in bilateral relations.”1Liu Jieyi,“Guoji fangkuosan zhanwang yu zhongguo de zhengce[Prospect of international nonproliferation and China’s policy]”,November 14,2002,accessed December 30,2006,http://www.china.com.cn/policy/txt/2002-11/21/content_5235650.htm.

C.Interaction of nonproliferation strategies between the two countries has increased.First of all,China and the U.S.share important consensus in maintaining and perfecting nonproliferation norms,especially safeguarding the effectiveness of the international nonproliferation regime.Since the 1980s,China　has　gradually　integrated　itselfinto　the　international nonproliferation regime,believing this regime to be an important component for global security.On the other hand,the U.S.also wants to further strengthen and improve the existing international nonproliferation regime.Second,common language has increased between China and the U.S.on such coercive measures as nonproliferation export control.The export controlsystemsofChinaand　theU.S.haveundergoneimportant transformations.China has transformed from administrative management under the planned economy to management on the basis of law under the market economy,establishing a legal system on export control that was basically completed by 2002.Nonproliferation is the fundamental purpose of China’s export control.The U.S.is also making efforts to transform its strategic export control system formed during the Cold War to a post-Cold War system by strengthening the pertinence of nonproliferation export control and upgrading the effectiveness of its control as one of its core purposes for reforms.This has laid a solid foundation for the two countries to engage　in　cooperation.Even　on　rather　sensitive　issue　such　as nonproliferation sanctions,China and the U.S.have gradually reached certain consensus.For example,several times since 2006,China and the U.S.have supported the UN Security Council to pass resolutions for sanctions,sending warnings to regional hotspot countries and demonstrating the unified position of the international community.

A.The intense international proliferation situation has prompted China and the U.S.to strengthen their responses.Looking back on the history of international nuclear proliferation,there are roughly three phases.The first phase spanned from the 1950s to the mid-to-late 1960s,in which civil nuclear technology diffused widely,laying the foundation for some countries to develop nuclear weapons.The second phase lasted from the mid-to-late 1960s to the end of the Cold War,during which Israel,India,Pakistan,South Africa,South Korea,Iraq and Taiwan were secretly engaged in developing nuclear weapons.The third phase is the booming period:India and Pakistan began their nuclear tests in 1998,North Korea and Iran nuclear issues were intensifying respectively in 2002,and the secret nuclear development programs of Libya and Syria were exposed successively.The result of these nuclear issues has formed three hotspots in the Korean Peninsula,South Asia and the Middle East.This wave of nuclear proliferation has two features:first,from a geographical point of view,Asia,where China is located,has become the hardest-hit area;second,from the perspective of subject,countries and non-state actors seeking nuclear weapons are American rivals.Therefore,both China and the U.S.cannot detach themselves from this severe situation,which has provided strong driving force for both countries to cooperate in responding to the proliferation of nuclear weapons.

A.Multi-level communication and exchange on nonproliferation has deepened mutual understanding and trust between China and the United States.On the level of summit diplomacy,international or regional nonproliferation challenges such as the North Korea nuclear issue,the Iran nuclear issue and nuclear terrorism are unavoidable topics,from the Jiang Zemin-Bush meeting to the Hu Jintao-Bush meeting and Hu Jintao-Obama meeting,from the talk at the Annenberg Retreat to the night talk at the Sea Terrace Islet,and from the autumn conversation at the White House to the long talk by the Western Lake.On the level of administrative departments,in addition to dialogues on thematic issues such as nuclear security and anti-nuclear smuggling,there is the policy dialogue led by the foreign affairs departments.China and the U.S.have established China-US consultation on strategic security,arms control and nonproliferation at the deputy minister’s level,which has held eight rounds of talks since 2002.In 2014,China and the U.S.set up a joint work group to deal with the proliferation　ofWMDs.This　was　the　firstspecially　designated anti-proliferation cooperation mechanism China had ever established with other major powers,and it has already assembled two meetings so far.On the civilian level,exchanges of information on nonproliferation by both think-tanks and universities in China and the U.S.have become frequent.For instance,China International Strategic Research Foundation and the Pacific Forum,to which the Center for Strategic and International Studies of the U.S.is affiliated,jointly hosted workshops on strategic nuclear relations and mutual strategic trust between China and the U.S.,holding discussions on mutual trust and cooperation between China and the U.S.in the field of nuclear nonproliferation.1Hu Yumin,“Tansuo xinxing zhanlue heguanxi[Exploring the new type of strategic nuclear relationship]”,People’s Daily,February 10,2015,accessed on January 7,2017,http://paper.people.com.cn/rmrb/html/2015-02/10/nw.D110000renmr_20150210_2-03.htm.The annual conference of the Chinese Scientists Group on Arms Control(CSGAC)and the International Confederation of Societies of Authors and Composers(CISAC)involves hot and frontline issues such as regional nonproliferation and nuclear forensic science.1Accessed on January 7,2017,http://www.caep.ac.cn/xwzx/yw/20142.shtml.In nonproliferation export control,Chinese enterprises have maintained cooperative relations with some American institutions.For instance,the Center for International Trade and Security of the University of Georgia and some other institutions have helped some Chinese corporations strengthen their internal control mechanisms.These exchanges have played an active role in stabilizing bilateral relations overall.Since 9/11,the China-US relationship has undergone highs and lows,starting low and ending high during the Bush administration,and starting high and ending low in the Obama administration.Nonetheless,concerns over the proliferation crises have prompted China and the U.S.to maintain close communication in various nonproliferation hotspots,which has the desired effect of strengthening mutual understanding and trust.This is conducive for the decision makers of China and the U.S.to properly grasp the trajectory of China-US relations and avoid unnecessary conflicts and friction.

B.China-US nonproliferation cooperation has stabilized the situation in regional hotspots and ensured the security and development interests of China and the United States.China-US nonproliferation cooperation cannot solve every problem,just as the Six-Party Talks on the North Korea nuclear issue failed to stop DPRK from stepping over the nuclear threshold.But listening to each other’s opinions earnestly,caring for the other’s concerns,enhancing coordination and emphasizing problem resolution through diplomatic channels have ensured the stability of this regional situation and helped each country realize their respective fundamental interests.For China,China-US nonproliferation cooperation has eliminated the possibilities of chaos and war in China’s neighborhood,so that China may concentrate its energy on economic development.From 2001 to 2016,China’s GNP has grown by 6.7 times and risen from the 6th to the 2nd largest economy globally,taking a large step toward the goal of a prosperous,well-rounded society.In addition,by getting involved with the hot issues of nonproliferation,China has increased its international influence.For the U.S.,getting China’s cooperation in nonproliferation has reduced the cost to maintain its hegemony.On the Iran nuclear issue,China-US cooperation has peacefully mitigated the tense situation and reduced the potential threat to the United States.Furthermore,China’s participation in arms control agendas initiated by the U.S.,such as the Nuclear Security Summit,has enhanced the representativeness and influence of such initiatives and helped manifest American leadership in the global nonproliferation regime.

Nonproliferation has changed from a point of friction to a point of cooperation between China and the U.S.and has provided a bright spot in bilateralrelations,which　resulted　from　the　intense　international proliferation situation and the proactive strategic choices made by China and the United States.Conversely,nonproliferation cooperation has enhanced mutual trust between the two countries and greatly promoted the development of China-US relations.

Challenges and Opportunities

Currently,the world is undergoing fundamental changes,which will have a significant impact on the China-US nonproliferation cooperation model that has remained stable for over more than a decade.

I.China-US nonproliferation cooperation is facing new challenges

秋蚕后至桑树落叶前天气晴好，此时大部分害虫尚未进入冬眠，采取农业防治与化学防治相结合的方式可大量杀灭害虫。

A.The changes in the international nonproliferation agenda will reduce the grabs for China-US cooperation.First,the nuclear security issue was once the focus of China-US cooperation,but is now fading from the center stage of international nonproliferation.Nuclear security was the primary substance of the“nuclear-free world”concept advocated by Obama.But during the late Obama administration,with the status quo of global nuclear materials improving and the focus of American nuclear strategy turning toward the modernization of nuclear armament,American emphasis on nuclear security had been greatly reduced.In 2016,after the end of the Nuclear Security Summit process,American nuclear diplomacy boomed while Obama’s personal brand further cooled down.During his election campaign,Trump almost never mentioned the nuclear security issue,nor has he set international nuclear security cooperation as a priority for his administration after taking office.Although the existing China-US nuclear security cooperation is still continuing,it will,as feared,be confined to a technical level,rather than the focus of summit diplomacy.Second,humanitarian nuclear disarmament is rising abruptly,as outlawing nuclear weapons has become the focal issue that is overwhelming nonproliferation.Under its impetus,the UN passed the Treaty for the Prohibition of Nuclear Weapons in July of 2017,due in part to the efforts of the International Campaign to Abolish Nuclear Weapons(ICAN),who won the Nobel Peace Prize for this accomplishment.This has posed a challenge to China-US nonproliferation cooperation in two aspects.First,China has different views on the ICAN than the United States.China has acknowledged its final objective,but believes that it is unrealistic and too eager to succeed,which caused China to abstain during the negotiations on the Treaty for the Prohibition of Nuclear Weapons at the UN General Assembly.The U.S.was so concerned that it might weaken the basis for its extended deterrence and lead to the collapse of its alliance network,which is supported by nuclear power,that it rallied its allies to oppose it with all their strength.This will affect the ability of China and the U.S.to coordinate their positions under the five nuclear-country framework.Second,the ICAN will directly affect the agenda of the convention to review the Treaty on the Nonproliferation of Nuclear Weapons.Under such circumstances,there will be limited space for China and the U.S.to cooperate and enhance the international nonproliferation regime.

B.Periodic changes in regional nuclear proliferation hotspots has increased the difficulty for China to play the role as an honest middle man.Since 2015,international nuclear proliferation has gradually moved from the outbreak period to the plateau period after more than a decade of clamor.The plateau period has two features.First,horizontal proliferation has slowed down.The conclusion of the Iran nuclear agreement has relaxed the Iran nuclear issue,which had been a tense situation for 13 years,while the possibility for other nuclear hotspot countries,such as Japan and South Korea in East Asia as well as Egypt,Saudi Arabia and Turkey in the Middle East,to develop nuclear weapons in the near future is low,limited by either the　internaland　externalpoliticalenvironmentortheirtechnical capabilities.1Leonard S.Spector,“A Proliferation Plateau May Offer Unique Opportunities,”Arms Control Today,April 2016,accessed on January 7,2017,https://www.armscontrol.org/ACT/2016_04/Features/A-Proliferation-Plateau-May-Offer-Unique-Opportunities.Second,the risk of vertical proliferation by those countries that have stepped over the nuclear threshold are rising.In South Asia,the nuclear and missile race between India and Pakistan is intensifying.In Northeast Asia,the nuclear and missile capability of DPRK is increasing,with the line of parallel development of nuclear weapons and economy written into both its national and party constitutions,and the difficult reality of having nuclear weapons reversed in a short time period.Under such circumstances,as America’s demand for China in nonproliferation will likely be reduced,it will be more and more difficult for China to play the role as an honest middle man between the U.S.and nuclear hotspot countries.

(3) 三种因素都会对排水管的淤塞造成影响，随着水力梯度、排水管壁面积以及土体黏粒含量的增大，排水管的淤塞会有不同程度上的加剧。

C.The U.S.military defense against China is increasing,which has contributed interference to China-US nonproliferation cooperation.Of late,America’s judgment on international security has changed greatly,believing that the international security pattern is turning from the unipolar system of the post-Cold War period to a new era of major power competition,ending in the geopolitical game re-occurring.Meanwhile,the primary strategic goal of the U.S.has also changed from counter-terrorism and　nonproliferation　to　preventing　regionalhegemonicstatesfrom emerging in Eurasia.The American National Military Strategy of 2015 claimed that the future combat pattern will return to great power conflict.To guard against and suppress China,the U.S.has pursued the Asia-Pacific Re-balancing strategy and given full play to various resources to seek competitive advantages for the future.Disturbed by other geopolitical calculations,nonproliferation has been distorted and abused,which has greatly exerted a negative impact on China-US cooperation.First,the U.S.has further restricted high-tech export control on China rather than relaxing it,regardlessofChinaand　the　U.S.strengthening　nonproliferation cooperation.Although the U.S.National Defense Authorization Act of 2013 has relaxed export control on commercial satellites and other relevant items,China is not allowed to import the aforementioned items from the U.S.,as it ranks alongside DPRK,Iran and Sudan on the list of so-called“countries supporting terrorism”.This has seriously impeded the smooth development of high-tech trade between China and the U.S.,and has affected the enthusiasm of Chinese enterprises to further improve their internal control mechanisms for export control.Second,the U.S.has insisted on arms sales to Taiwan while demanding China to strengthen export control to enhance its self-security,which has undermined China’s security interests.The primary objective of regional nuclear hotspot countries in developing nuclear weapons is to deter the U.S.and its allies rather than China.China’s active participation in resolving regional nuclear issues and strengthening export control have fully alleviated American security concerns.But on the issue of arms sales to Taiwan by the U.S.,an issue concerning China’s core interests,China has never received good faith feedback from the United States.From the present situation,the impulse of the U.S.to play the“Taiwan card”will only get more intense.After being elected as the U.S.President,Trump deliberately challenged the“One China”principle and broke the convention that had been established since normalizing diplomatic relations between China and the U.S.by talking to Tsai Ing-wen on the phone.With China’s diplomacy attaching more importance to enthusiasm and action,it is quite likely that relevant countermeasures will not be confined to relatively passive methods such as postponing the dialogue on arms control and nonproliferation.Third,interference from geopolitical games to the U.S.policy on nonproliferation will increase.The most outstanding example can be seen in the case where the U.S.changed its nuclear policy toward India.In 1998,after India’s first nuclear test,China and the U.S.coordinated their positions and supported the resolutions passed by the UN Security Council to condemn India.But the U.S.,starting in the Bush Jr.administration and continuing in the Obama administration,has gradually set aside the nonproliferation principles to rope India into its strategy for containing China.The U.S.signed the Civilian Nuclear Energy Cooperation Agreement with India first,and then encouraged the NSG to engage in civilian nuclear cooperation with India,which were followed by American efforts to support India in joining such nonproliferation　exportcontrolregimesastheNSG　and　(Missile Technology Control Regime)MTCR.China and the U.S.had a major disagreement on whether or not to allow India to join the NSG as an exception.According to the guiding rule of the NSG,the NSG member states should sign and approve the NPT,which India has not done yet.The U.S.hoped the NSG would give India a privilege and let it in to the group as a special admission.However,China,New Zealand,Ireland,Turkey,South Africa and Austria were worried that this double-standard would seriously undermine the authority and credibility of the international nonproliferation regime and stimulate a nuclear arms race in South Asia.Therefore,they insisted on making a uniform standard for non-member states of the NPT to join the NSG before considering India’s case.This problem　may　continue　to　ferment,　interfering　with　China-US nonproliferation cooperation.

D.The debate on nonproliferation between China and the U.S.is likely to heat up.First,the different positions between China and the U.S.on nonproliferation will likely be forced to be highlighted again.Compared to the Obama administration,the Trump administration is more inclined to use force for nonproliferation.Within his first hundred days in office,Trump ordered an air raid on a military airport of the Syrian government in retaliation　forthechemicalweapon　attacksin　Syria,which　was immediately followed by ordering U.S.carriers to the Korean Peninsula for deterrence.This move will likely increase the risk of war and is unfavorable to the stability of the regional situation.Yet,for China,no war and no chaos,similar to nonproliferation,is also an important strategic goal.The differences between China and the U.S.may touch on more contradictions.Second,different attitudes toward the UN may also affect China-US cooperation.The UN is an important platform for dealing with nonproliferation issues,not only playing a dominating role in coping with regional nuclear hotspots,but also acting as the major policy maker of international nonproliferation rules.Nevertheless,the attitude of China and the U.S.toward the UN is developing in opposite directions.China has adhered to the principle of multilateralism and supported the UN to play a central role in international affairs including nonproliferation.In May of 2016,China set up the China-UN Peace and Development Fund Agreement to increase financial assistance to the peace and development cause of the UN.However,Trump,as an anti-establishment figure,has doubted multilateral institutions such as the UN.He called the UN an“exclusive club for empty talks”,saying that the U.S.“would keep a completely different relationship with the UN”during his administration.The different attitudes between China and the U.S.toward the UN will certainly impact their nonproliferation consultation and coordination within the UN framework.

II.Opportunities for China-US nonproliferation cooperation.Changes in the international situation breed new hope

A.The common interests of China and the U.S.in maintaining global and regional order have seen an increase.With the development of China’s foreign trade and investments abroad speeding up,a new dynamic has been added to China-US nonproliferation cooperation,namely common efforts to promote global governance,maintain global and regional stability,and prevent the international trade system and investment environment from worsening.The U.S.and China are the first and second largest capital exporters and goods trading countries in the world,with interests spreading globally and pressing demands for global security.Nonetheless,nuclear proliferation has intensified the situation in the hotspots regions in the Middle East and South Asia,seriously threatening the security of international trade passages and the safety of overseas personnel,and worsening the investment environment,which both China and the U.S.would　notlike　to　see.Nonproliferation　ofWMDs,maintaining international security,and ensuring the smooth operation of international trade and investment are in line with the common interests of both countries.

B.Strengthening China’s nonproliferation capability will create new opportunities for China-US cooperation.In recent years,China has further deepened its understanding of nonproliferation.In January of 2017,President Xi Jinping made a speech in Geneva on the community of a shared future for humanity,which comprehensively answered the question to the international community about what China would do after becoming a major world power.Of most importance in his speech,President Xi Jinping　said,“Completely　prohibitand　eventually　destructnuclear weapons thoroughly to make a nuclear-free world.”1Xi Jinping,“Gongtong goujian renlei mingyun gongtongti—zai lianheguo rineiwa zongbu de yanjiang[Jointly constructing the community of a shared future for humanity]”,Speech delivered at the UN headquarters in Geneva,January 18,2017,accessed on May 1,2017,http://news.xinhuanet.com/world/2017-01/19/c_1120340081.htm.This indicates that the nuclear-free world China has long insisted on is no longer a far-reaching arms control target,but an integral component of the Chinese world dream.In its efforts to achieve this target,China’s construction of nonproliferation mechanisms and formulation of policies and regulations are improving.The National Security Law,promulgated in July of 2015,has listed nuclear security as a major national security task.Laws and regulations closely related　to　specialentity　protection　and　exportcontrol,such　as Anti-Terrorism Law,Atomic Energy Law,Nuclear Safety Law,Nuclear Security Regulations,Measures for Supervision and Administration of Military Nuclear Safety Equipment,and Measures for Nuclear Safety Supervision and Administration of Radioactive Materials Transportation in Military Industry,have been or will be introduced shortly.China’s construction　ofnonproliferation　mechanismshasmadecontinuous progress:the Department of Arms Control of the Chinese Foreign Ministry has specially set up the Division of Nonproliferation;the two divisions specially charged with export control affairs in the Ministry of Commerce of the People's Republic of China(MOFCOM)have been upgraded into the Bureau of Industrial Safety and Import and Export Control;China Atomic Energy Authority has set up the National Nuclear Security Technology Center;relevant departments have strengthened inter-departmental coordination and set up inter-departmental emergency coordination mechanisms for nonproliferation export control.1Information Office of the State Council,Zhongguo de junkong,caijun yu fangkuosan nuli,[China’s efforts in arms control,disarmament and nonproliferation],September 1,2005,accessed January 7,2017,http://www.scio.gov.cn/zfbps/gfbps/2005/Document/308253/308253.htm.This will greatly　facilitate　China-US　nonproliferation　cooperation.First,the Chinese solution will provide new ideas for China and the U.S.to jointly deal with regional proliferation issues.China has more actively proposed its solutions for nonproliferation issues,leading the development of the situation in a positive direction.For example,with regard to the deadlock in the North Korea nuclear issue,China has proposed the solution of“paralleldevelopment” ofdenuclearization　in　the　peninsula　and mechanism conversion from truce to peace,as well as the“double pause”solutions,putting the urgent demands of both the U.S.and DPRK on the table,which is the right way to resolve the issue,as both the present and the future have been considered and tallied with the reality of the situation.Second,China and the U.S.may jointly develop and provide public goods for nonproliferation.In nuclear security,China and the U.S.may strengthen communication and exchange by using the nuclear safety demonstration center and China Custom’s anti-radioactive detection training center they jointly built to provide training and raise the nuclear security level in the Asia-Pacific region.In supply chain security,China and the U.S.may engage in more technical cooperation.For instance,the Port of Shanghai,in conjunction with the U.S.Port of Savannah,has developed　electronic　container　tagging　to　monitor　the　entire transportation process,which has improved the safety of logistics.In early warning stages of proliferation risks,China may share information with the U.S.to raise early warning capabilities.For example,China Arms Control and Disarmament Association and China Institute of Nuclear Science and Technology Information and Economics jointly issued the Research Report on Nuclear Materials in Japan,which elaborates on the production and stockpiling of nuclear materials in Japan.This has provided more reference data for China and the U.S.to assess regional proliferation risks.

C.Proliferation issues related to terrorism remain the focus of China-US cooperation.The pressure of counter terrorism facing China and the U.S.is increasing.For China,terrorist activities conducted by the East Turkistan Islamic group have occurred very frequently,manifesting a trend of collusion of terrorist forces inside and outside of the autonomous region as well as inside and outside of China.They have engaged in migratory Jihadism in conspiracy with al-Qaeda and the Islamic State(IS)to launch terrorist attacks.For the U.S.,although the IS has been badly hit in the Middle East,it is seeking to launch exterior-line operations and speed up the expansion of its influence to Europe,Africa,South Asia and even the continental U.S.itself,putting the U.S.face-to-face with the risks of a new wave of terrorist attacks.Against such backdrop,the demand for counter terrorism cooperation between China and the U.S.is rising.In July of 2014,the two countries started the counter terrorism consultation at the deputy minister’s level,which so far has held three rounds of talks.Preventing terrorists from obtaining weapons of any kind,especially WMDs,istheprimary　objectiveofChina-US　counterterrorism cooperation.In addition,given the variability of the means of terrorist attacks,China-US counter terrorism cooperation should be extended to other areas of nonproliferation.For instance,Improvised Explosive Devices(IEDs)are easy to make at a low cost,but have the high risk of being used in terrorist attacks.Officials and specialists in China and the U.S.have already begun discussions on how to combat illegal circulation of dual-purpose explosives and chemicals to prevent terrorists from using them to make IEDs.1Diqilun zhongmei zhanlue yu jingji duihua kuangjiaxia zhanlue duihua juti chengguo qingdan[List of specific results of strategic dialogue under the Framework of the 7th Round of China-US Strategic and Economic Dialogue],June 25,2015,accessed January 7,2017,http://www.fmprc.gov.cn/mfa_chn/zyxw_602251/t1276058.shtml.

Conclusion

With changes in the international pattern and American political situation,the China-US relationship is facing a series of treacherous shoals.Under such circumstances,it is of great importance to maintain and strengthen China-US cooperation in the field of nonproliferation as well as continue to make it play the role of stabilizer for their bilateral relations.However,China-US cooperation in nonproliferation has been impacted due to these changes.We must not take it for granted that the effective model of China-US cooperation in the past decade or so will remain effective in the future.China and the U.S.should timely adjust the focus of their nonproliferation cooperation on a more equal basis,expanding common interests and exploring new patterns for cooperation so as to create a model for the two countries to join hands in global governance and maintenance of regional order.