The tragedy of September 11, 2001 had enormous impacts on both military and civil aviation. Since then, airport security has been far stricter, while the US military air defense has also changed . A significantly greater percentage of Air National Guardsmen became combat veterans after 9/11 compared to their pre-9/11 counterparts.
9/11 ushered in a two-decade-long era for the United States Air Force and Air National Guard. Over 24 years have elapsed since the Twin Towers came down. Since then, the Air Force (along with the Air National Guard) has conducted innumerable combat missions in Afghanistan, Iraq, Syria, Libya, and elsewhere (most recently in Syria and Yemen).
However, the focus of the Air Force is shifting to a new era of Great Power Competition with China . The US has completely or mostly disengaged from Afghanistan and Iraq and is refocusing on the Asia-Pacific with eyes increasingly on Guam (the US's 'unsinkable aircraft carrier .' The deceptively peaceful world of 2001 By 2001, the Cold War had been over for a decade, a new era of Great Power Competition with China was a long way off, and the United States was at the height of its relative power.
Some dubbed this period of peace the Pax Americana. While there were hotspots around the world (including in the Middle East), these seemed very distant from American shores. The 1990s was also a period of the so-called "peace dividend," where the end of the Cold War allowed Western nations in Europe and the United State.