After the dissolution of the Soviet Union in 1991 , the United States was the world 's dominant military power and Japan , sometimes seen as the largest economic rival to the U.S. , was caught in a period of stagnation . China was emerging as the U.S. 's foremost trading competitor in more and more areas . Localized conflicts such as those in Haiti and the Balkans prompted President Bill Clinton to send in U.S. troops as peacekeepers , reviving the Cold-War-era controversy about whether policing the rest of the world was a proper U.S. role . Islamic radicals overseas loudly threatened assaults against the U.S. for its ongoing military presence in the Middle East , and even staged the first World Trade Center attack , a truck bombing in New York 's twin towers , in 1993 , as well as a number of deadly attacks on U.S. interests abroad
first World Trade Center attack
1993 World Trade Center bombing
History of the United States (1991–2008)