Abstract：In the late 1980s and early 1990s, with the transformation of the East European socialist states, the reunification of Germany, and the disintegration of the Soviet Union, the Cold War ended, and the United States found itself at another watershed. However, it is more difficult to define and determine the interests, objectives, and means of American foreign strategy. 

　　　The Bush government advocated a foreign strategy of “New World Order”. The concept of “New World Order” includes the emphasis of American leadership in world affairs and the creation of a new “American century”. However, it was criticized for being ambiguous and impractical. Clinton paid more attention to internal affairs and promoted a foreign strategy of “Engagement and Enlargement”, which accelerated its economic development and enhanced its leadership. In the year of 2000, George W. Bush won the presidency campaign. He acted a foreign strategy of Unilateralism. However, in recent years, America has been in troubles. Many powers are rising quickly, but at the same time, America sinks into Afghanistan and Iraq war. NPRK and Iran are busy developing their nuclear weapons, imposing threat to regional and international security. Undoubtedly, America encounters more problems in the post-cold war era. 

　　　In the future, America has to adjust its foreign strategies to cooperate with others and depend more on its soft powers to maintain its national interests,.

Key Words：US; foreign strategy; post-cold war era; cooperation 

中文摘要：20世纪80年代末90年代初，伴随着东欧巨变、两德统一和苏联解体，冷战宣告结束。美国也面临着全新的国际形势。但是，要重新寻找确定美国的国家利益、战略目标及其实现的途径却变得更加困难。 

　　老布什上台后，指定了“新世界秩序”的对外战略政策，强调要确保美国在世界事务中的领导地位以实现“美国世纪”，但因其模糊性和不具操作性而遭到广泛批评。因此，克林顿得以在四年后的选举中胜出。克林顿政府推行“参与和扩展”的对外战略，振兴了美国经济，增强了美国对世界的影响力和领导力。2000年小布什上台后，大力推行单边主义政策。但近年来却遇到了不少麻烦。在其他国家迅速崛起的同时，美国却深陷阿富汗战争和伊拉克战争的泥潭，纠缠于朝鲜和伊朗的核问题而不得脱身。毫无疑问，美国在后冷战时代面临着更多的问题。

　　因而，美国今后必须调整其外交战略，与其他国家进行合作，并更多地依靠软力量来维护其国家利益。

关键词：美国；外交战略；后冷战时代；合作