对本周与奥巴马总统的会晤成果，中国国家主席习近平和他的团队应该感到非常满意和宽慰。他们出入华盛顿没有遇到任何公开的尴尬和分歧。就连总统奥巴马、副总统拜登和国务卿克里公开提到的少数分歧，也只是顺嘴而出的两国复杂关系中正常的、需要加以调理的部分。正如奥巴马总统在联合记者会上说的：“我致力于扩大我们的合作，即使我们解决分歧，也是坦率而有建设性的。这就是此次访问中，在昨晚的工作餐和今天的会晤中，习主席和我所做的事情。”这体现了奥巴马总统的个人外交风格，因为他不是在公开场合针锋相对而私底下又彬彬有礼的人。习近平主席公开露面的时候也庄重平和。两人都试图强调双边关系中积极的一面。

奥巴马总统和第一夫人米歇尔在白宫设宴欢迎中国国家主席习近平访美。

2015年9月25日，中国国家主席习近平（右二）和夫人彭丽媛（左一）在美国总统奥巴马和第一夫人米歇尔举行的欢迎仪式后在白宫的阳台上向大家挥手致意。

因此，从中国角度看，主要目标已经完成：大量峰会盛况的照片（有仪仗队的欢迎仪式和精心准备的国宴）和最少的公开尴尬。习近平主席和他的代表团遇到了许多示威者，包括白宫和国务院外的示威，玫瑰园的联合记者会自始自终都能听到他们的抗议声。但总体而言，媒体情况和访问的象征意文应该让北京感到满意。

实际上，这次峰会传递出的主要信息，是在全球治理的一系列问题上，两个大国都在尽其所能进行合作。美中有关“全球和地区挑战”的详细“情况说明书”中，列举了双方在特定领域的合作。这在两国元首和副总统拜登、国务卿克里的公开讲话中也有明确表示。

显然，奥巴马政府仍强调让中国成为全球治理合作伙伴。自从七年前开始执政，这就是他们工作要务。这也是奥巴马2009年对中国进行国事访问的核心目的，但是被中方拒绝了。当时，中国在多边舞台上仍缺乏信心，它质疑美国让中国成为“负责任的国际利益攸关方”的要求，认为那是让中国在全球过度扩张、阻止中国崛起的另一个阴谋。

但自那以后，中国在国际上信心增强，并越来越多地在维和、公共卫生、反恐、气候变化、核安全、打击海盗、可持续发展、人道主义救援及其他各类全球治理活动中出力。因此，两个大国合作的可能性增加。习近平自已发出的信息是，他更能接受中国的外交行动主义。就像奥巴马在联合记者会上对他说的：“习主席，我要再次感谢你对扩大我们两国之间合作所作出的承诺。我相信这再次提醒我们，当我们努力缩小彼此的分歧时，我们就能继续推动两国的共同利益，这不仅利于两国，而且造福世界。”

即使没有G2集团，近年的全球治理合作也被证明是弥补战略关系的粘合剂。今年夏天的战略经济对话同样对全球合作寄予厚望。所以，在两国政府喧嚣不绝的分歧背后，某些稳定要素也许正在紧张关系下重新形成。

全球治理对世界和两个大国都很重要，但它对于全面恢复困顿中的中美关系并不是万能的。因由众所周知，它们是现实的、深层次的，很难解决。而加以管控，防止失控行为干扰双边关系的其他领域，需要外交造诣。偶尔，双方可以取得实质性进展，就像此次峰会涉及的网络商业间谍问题，以及为避免海上或空中突发事件升级为武装冲突，双方构建了军事建立信任措施。

这些敏感和困难领域取得的进展，只能通过频繁的外交接触才能实现，而峰会为达成共识提供了必要的机会，这是次级官员难以做到的（这也即是所谓的“加速行动型外交”）。它本身使定期举行峰会有了充足理由。举行峰会的另一个理由是，政府最高级别领导人直接坦率地就存在严重分歧的领域进行会谈，可以避免问题恶化和转移。第三个理由就是，它能最大限度地促成具体领域的实质性合作。

就这三方面来说，2015年的习奥会应该说是一次成功。地球上两个最大国家取得了进展，建立了信任，稳定了关系。问题是，这种状态能维持多久？过去10年的几次峰会，都显示了同样的稳定作用，但仅仅只个月之后，双方又重新开始猜疑、争执和相互攻讦。即使无他，这也是每6个月举行一次双边首脑会晤（不必是国事访问）的强大理由。美中两国和世界需要峰会所带来的稳定。自从尼克松总统和毛主席1972年会面以来，中美关系史已经清楚表明，要保持两国关系不脱轨，双方元首必须参与、介入。

China's President Xi Jinping and his team should be very pleased—and very relieved— with the outcome of the summit meeting with President Obama this week. They got in and out of Washington without any public embarrassments or disagreements. Even the few public references to disagreements that President Obama, Vice President Biden, and Secretary of State Kerry made were contextualized as the normal part of a complex relationship that had to be managed. As President Obama noted at their joint press conference: “I'm committed to expanding our cooperation, even as we address disagreements candidly and constructively. That's what President Xi and I have done on this visit—during our working dinner last night and our meetings today.” This is a reflection of President Obama's personal diplomatic style, as he is not confrontational in public and polite in private. President Xi was also dignified and calm in all of his public appearances. Both men sought to accent the positive in the relationship.

President Barack Obama and First Lady Michelle Obama hosted a state dinner at the White House in honor of Chinese President Xi Jinping’s visit to the United States.

Chinese President Xi Jinping, second from right, and his wife Peng Liyuan, left, wave hands after US President Barack Obama and First Lady Michelle Obama hold a welcome ceremony in White House, Sept 25, 2015.[Photo/Agencies]

Thus, from the Chinese perspective, a primary goal was accomplished: lots of photos of summit pageantry (Honor Guard welcoming ceremony and elaborate state dinner) and minimal public embarrassment. President Xi and his delegation were exposed to many demonstrators—including just outside the White House and State Department and their protest were audible throughout the Rose Garden joint press conference. Overall, though, the media “optics” and symbolism of the visit should have satisfied Beijing.

Substantively, the major message conveyed by the summit was of the world's two major powers doing their best to work together on a broad menu of global governance issues. A detailed “factsheet” of US-China perspectives on “global and regional challenges” enumerated specific areas of cooperation. This was also apparent in both president's public comments, as well as those by Vice President Biden and Secretary Kerry.

Clearly, the Obama administration still places a high premium on China as a partner in global governance. This was their priority when they came into office seven years ago and was the centerpiece of Obama's own November 2009 state visit to China—only to be rebuffed by the Chinese side. At that time, China still lacked confidence in the multilateral arena and suspiciously viewed American entreaties for becoming a “responsible international stakeholder” as another plot to retard China's rise by getting it overextended in the world.

But, in the interim, China has gained more multilateral confidence and has stepped up its contributions to various global governance activities—in peacekeeping, public health, counter-terrorism, climate change, nuclear security, anti-piracy, sustainable development, humanitarian assistance and disaster relief, and other areas—and it is thus now more possible for the two powers to cooperate. Xi Jinping himself signaled a greater receptivity to China's diplomatic activism. As President Obama told him at their joint press conference: “President Xi, I want to thank you again for expanding your commitment to cooperation between our nations. I believe that it's another reminder that as we work to narrow our differences, we can continue to advance our mutual interests for the benefit not only of our two peoples, but for the benefit of the world.”

Even if it is not a G-2, global governance cooperation could prove to be the missing “glue” to the strategic relationship in recent years. This summer's Strategic and Economic Dialogue similarly placed a premium on global cooperation. So, almost by stealth and amid much clamor over the two government's many differences, perhaps some ballast is being rebuilt in the frayed relationship.

While important for the world as well as both powers, global governance cooperation is not a panacea for restoring full health to the troubled Sino-American relationship. The reasons for the troubles are well-known, they are real and run deep, and not easily resolved. Management of them—containing them from hemorrhaging into other areas of the relationship—is a diplomatic accomplishment. Occasionally—as appears to potentially be the case with the cyber corporate espionage issue at this summit—actual tangible progress can be made. Another example are military confidence building measures to avoid accidents at sea or in the air that could escalate into an armed confrontation.

Progress in sensitive and difficult areas such as these can be achieved only through intensive diplomatic engagement—and presidential summits offer the needed opportunity to forge consensus that are difficult to reach by second-level officials (this is known as “action-forcing diplomacy”). That, in itself, is sufficient reason to hold periodic presidential summits. The other reason, though, is for direct and straightforward discussions at the highest levels of government on areas of serious disagreement—lest they fester and metastasize. The third reason is to forge tangible cooperation in specific areas wherever possible.

In these three regards, the 2015 Obama-Xi Summit must be judged a success. Progress was made, trust was built, and the two great powers on the planet have stabilized their relations. The question is: how long will it last? Previous summits over the past decade have exhibited a same stabilizing pattern—only for mistrust, disagreements, and acrimony to return after a few months' passage of time. If nothing else, that is a strong rationale to hold bilateral summits (which need not be state visits) at regular six-month intervals. Both nations and the world need the stability summits provide. The history of Sino-American relations since President Nixon and Chairman Mao met back in 1972 shows clearly that presidential involvement and investment is imperative to keeping the relationship on track.