摘要
In the 1990s,the dramatic changes in the Soviet Union and East Europe put an end to the Cold War stand-off between the United States and the Soviet Union.The world entered the post-Cold War era with the United States as the world's sole superpower.In the 21^(st) century,the outbreak of the 9/11 terrorist attacks brought the United States into two wars in Iraq and Afghanistan.The U.S.
In the 1990s, the dramatic changes in the Soviet Union and East Europe put an end to the Cold War stand-off between the United States and the Soviet Union. The world entered the post-Cold War era with the United States as the world＇s sole superpower. In the 21st century, the outbreak of the 9/11 terrorist attacks brought the United States into two wars in Iraq and Afghanistan.
