After the Cold War , the United States has been focusing on modern conflicts in the Middle East and nuclear programs in North Korea . The beginning of the 21st century saw the September 11 attacks by Al-Qaeda in 2001 , which was followed by the wars in Afghanistan and Iraq . In 2008 , the United States had its worst economic crisis since the Great Depression , which was followed by slower-than-usual rates of economic growth during the 2010s
September 11 attacks
September 11 attacks
History of the United States