2017年4月7日，美國總統特朗普（左）和中國國家主席習近平在美國佛羅里達州的棕櫚灘舉行雙邊會議之後，在海湖莊園前的院子里散布。（路透社/卡洛斯·巴里亞）

近日，中美首輪外交安全對話在華盛頓閉幕。美國國務卿蒂勒森、國防部長馬蒂斯都公開表示，此次對話富有成果。今年4月中美兩國元首舉行海湖莊園會晤，雙方同意建立新型的政策溝通與協調機制，外交安全對話是其中之一。下個月，中美還將舉行“全面經濟對話”。習近平主席與特朗普總統也將在德國漢堡G20峰會期間再度舉行會晤。這些互動有助於使國際社會增強對中美關係的穩定預期。

特朗普政府上台後，在處理對華關係上日益謹慎，並釋放出若干積極信號。正如國務卿蒂勒森所強調的，過去40多年美中關係發展取得巨大成就，雙方需要對下一個40年的兩國關係進行積極塑造。美方提出要施行“建設性的、以結果為導向的”對華政策，這得到了中國方面的響應。無論是應對中美經貿摩擦的“百日計劃”，還是雙方針對朝鮮核和導彈問題的密切政策協調，都體現出中美希望建設性管控分歧，並進一步培育“合作的習慣”。

此次外交安全對話期間，雙方再次表明了推動中美關係良性發展的戰略意圖，同意共同促進亞太地區和平、穩定與繁榮，並決定就改善兩國互動的基本原則進行討論。這並非外交辭令，或意味着雙方將就應對南海爭端和海上安全等問題嘗試新的策略。此外，中美重申致力於以全面、可核查、不可逆的方式實現朝鮮半島無核化的目標。

在兩軍關係方面，中央軍委聯合參謀長將加強與美軍參聯會的溝通，這將有效減少彼此誤判和軍事衝突的風險。在外空、網絡空間等戰略安全領域，中美將探討新的建立信任措施。雙方還將就打擊網絡恐怖主義、反恐怖融資、加強非洲第三國維和能力建設等開展合作。中美兩軍關係預計在未來數年還會出現新的“亮點”。

由此可見，過去幾個月來，中美關係在兩國元首的戰略引導之下開始呈現不少積極進展。然而，不可忽視的是，兩國關係也存在一些隱憂。首先，美國對華經貿政策可能會出現新的負面變化。比如，共和党參議員約翰·科寧、共和黨眾議員羅伯特·皮滕傑等正在起草旨在強化對中國在美投資審查的法案。由財政部主管的外國投資委員會（CFIUS）可能會設立專門機構負責處理涉及中國企業的交易計劃。此舉將向中國釋放非常不好的信號，使本來應當成為中美關係新支柱的投資關係受到損害。此外，美國商業界對中美“百日計劃”仍抱有不滿，認為還遠沒有達到“互惠”目標。

其次，美國方面在朝鮮問題上對中國的耐心或許正在下降。特朗普總統近期在推特上發文，對中國對朝鮮並未施加足夠大壓力暗示不滿。隨着被朝鮮釋放的美國大學生奧托·瓦姆比爾的死亡，美國國內要求狠狠“教訓”平壤的聲音在上升。特朗普曾表示，如果中國在朝鮮問題上合作，就會在經貿方面降低對華壓力。這種“議題掛鉤”策略的風險性值得充分警惕。眾議院軍事委員會主席索恩伯里等人要求美國政府強化與台灣的軍事關係。美國打台灣牌將不可避免地阻礙中美在朝鮮問題上合作。加之韓國新政府醞釀調整對朝政策，中美在應對朝鮮核和導彈問題上的政策協調或許會更為複雜。

第三，南海地區目前雖然相對平靜，但不排除下半年出現新危機的可能性。5月底，特朗普政府上台後美軍首次在南海地區展開針對中國的“航行自由行動”，而且不再是簡單的“無害通過”，而是在美濟礁12海里內進行所謂“人員救援訓練”。越南總理阮春福近期也訪問美國，南海問題成為其與特朗普討論的主要議題。特朗普已將其親信、國家安全委員會副助理麥克法蘭派往新加坡出任大使，這被認為是美國希望強化對東南亞政策的信號。特朗普將在11月訪問越南、菲律賓等國，如果美國想要通過在南海問題上製造麻煩來為特朗普的亞洲之行“造勢”，這將成為中美關係的新危機。

總之，特朗普上任以來，中美關係的“好消息”多於“壞消息”，這也讓國際社會鬆了一口氣。中國方面應對“特朗普衝擊”的策略還是非常成功的：確立有效溝通管道、審慎應對“挑釁”、主動塑造“合作議程”。下半年，中國共產黨第十九次全國代表大會將舉行，穩定和積極的中美關係是中國領導人所希望看到的。特朗普政府也已經認識到，“'讓美國重新偉大'的道路需要途經北京”。在一個充滿動蕩、暴力和不確定性的世界，中美需要相向而行，為兩國民眾和國際社會提供更多的“戰略保證”。

U.S. President Donald Trump (L) and China's President Xi Jinping walk along the front patio of the Mar-a-Lago estate after a bilateral meeting in Palm Beach, Florida, U.S., April 7, 2017. REUTERS/Carlos Barria

Both US State Secretary Rex Tillerson and Defense Secretary James Mattis openly declared the just concluded first session of China-US Diplomatic and Security Dialogue (D&SD) a success. At their Mar-a-Lago meeting in April, the two countries' heads of state agreed to set up new policy communication and coordination mechanisms; D&SD is one of them. Next month, the two countries will hold their Comprehensive Economic Dialogue. Presidents Xi and Trump will meet again in Hamburg at the G20 summit. Such interaction is conducive to the international community's expectations of stable China-US relations.

Since taking office, the Trump administration has been increasingly prudent in handling ties with China, and released some positive signals. The US side's proposal of a “constructive, outcome-oriented” China policy has resonated positively with China. The “100-day plan” intended for resolving economic and trade frictions and their close consultations about North Korea's missile/nuclear programs are indications that both parties hope to constructively manage and control differences and further cultivate “a habit of cooperation”.

During the D&SD session, both parties displayed the strategic intention to promote virtuous development of bilateral ties, agreed to jointly promote peace, stability and prosperity in the Asia-Pacific, and decided to discuss improving basic principles for state-to-state interaction. This was no diplomatic rhetoric, or meant they would try new approaches to the South China Sea issue and maritime security. Besides, both sides reiterated their goal of comprehensive, verifiable, and irreversible denuclearization of the Korean Peninsula.

In military-to-military relations, enhanced communication between Chinese and US Joint Chiefs of Staff will effectively reduce risks of misjudgment and military conflict. The two parties will explore confidence-building measures in such fields of strategic security as outer space and cyberspace. They will also collaborate in such areas as cracking down on cyber terrorism and terrorist fund-raising. Bilateral military ties may see more bright spots in the next few years.

Under the strategic guidance of both heads of state, China-US relations displayed many positive developments in the past few months. Yet undeniably there are some hidden troubles in the relationship. First, US economic and trade policies regarding China may face rocky times. For instance, Republic Senators John Cornin and Robert Pittenger are drafting a bill aimed at enhancing examination of Chinese investments. The Committee on Foreign Investment in the US under the US Treasury may set up a special department charged with handling transaction plans involving Chinese firms. Such a move will send a very bad message to China, and harm investment relations, which should otherwise become a new pillar for China-US relations. Besides, US business circles still have complaints about the “100-day plan”, believing it is far from the goal of “reciprocity”.

Second, US patience with China on the North Korea issue may be slipping. President Trump's recent tweets hinted at dissatisfaction with China for failing to mount sufficient pressure on Pyongyang. Following the death of Otto Warmbier, the American student just released by North Korea, voices for punishing Pyongyang are on the rise in the US. Trump has stated that if China cooperates on the North Korea issue, he would reduce pressures in economy and trade. The risk of such an issue-linkage strategy deserves full alert. People like Mac Thornberry, chairman of the US House of Representatives Armed Services Committee, are calling on the government to strengthen military relations with Taiwan. It will inevitably sabotage China-US cooperation on North Korea if Washington plays the “Taiwan card”. With the new government of South Korea reviewing its North Korea policy, things could become even more complicated for China-US policy coordination on Pyongyang's missile/nuclear programs.

Third, despite the relative peace in the South China Sea, the possibility of new crises in the second half of the year cannot be excluded. At the end of May, the US military held its first “freedom of navigation operation” against China since the Trump administration assumed office. Rather than a simple “innocent passage”, it featured a so-called “personnel rescue drill” within 12 nautical miles of China's Meiji Reef. The South China Sea was the main topic during the recent meeting between Trump and Vietnamese Prime Minister Nguyen Xuan Phuc when the latter visited the US. That Trump has appointed his deputy national security adviser KT McFarland as US ambassador to Singapore has been read as a sign that the US wants to strengthen its Southeast Asia position. Trump is to visit Vietnam and the Philippines in November. If the US wants to prepare public opinion for Trump's Asia visit by making troubles regarding the South China Sea, this will become a new crisis for China-US relations.

Since there has been more “good news” than “bad news” in China-US relations since the inception of the Trump administration, the international community has given a sigh of relief. The Chinese strategy for coping with the “Trump shock” — establishing effective channels of communication, prudently dealing with “provocations”, actively formulating an “agenda of cooperation” — has been very successful. The Communist Party of China will hold its 19th National Congress later this year, and Chinese leaders will want to see stable and positive China-US relations. The Trump administration has also realized that “the road to Making America Great Again runs through Beijing”.(Michael Pillsbury, “The Road to Making America Great Again Runs Through Beijing: Emerging Chinese Views of Donald Trump,” Hudson Institute, January 13, 2017). In a world full of turbulence, violence and uncertainty, China and the US need to meet each other halfway, and come up with more “strategic reassurance” for people of both countries as well as the international community.