美国对G20的认知与政策反应:以G20杭州峰会与汉堡峰会为例

The United States’ Cognition and Policy Response to the G20: Case Studies of Hangzhou Summit and Hamburg Summit

自2008年金融危机以来，二十国集团（G20）升级为领导人峰会，致力于应对金融危机，促进世界经济的复苏与增长。美国作为G20的发起国积极参与这一机制，其参与方式呈现出主导性、协商性、变化性的特点。在G20杭州峰会与汉堡峰会上，美国充分展示了其参与该机制的行为特征，中关两国共同在G20议程协商与设置方面发挥了典范作用，并在不少具体议题领域与G20其它成员国达成一致。然而，在美国经济日渐向好、国内政治变化和对外战略调整的背景下，未来美国对G20的态度具有很大的不确定性。这已在汉堡峰会上初露端倪。因此，新一届美国政府的G20政策取向值得进一步观察和分析。

Since the financial crisis in 2008, the G20 has been upgraded to the leaders＇ summit which is committed to dealing with the financial crises and promoting world economic recovery and growth. As a sponsor of the G20, the United States is actively involved in this mechanism, and plays a dominant, consultative, changing role. At the G20 summit in Hangzhou, the United States fully demonstrated its behavioral characteristics participating in the system. Besides, China and the United States jointly set up a model in the G20 agenda negotiations and settings. However, in the context of its economic growth and domestic political change in the future, especially since Donald Trump was elected as the 45th President of the United States in 2016, the attitude of the United States to many kinds of multilateral mechanism including G20 is very uncertain, which was fully demonstrated at the Hamburg Summit. Thus, the new U.S. government＇s G20 policy orientation is worth further observation and discussion.