I watched Stanley Kubrick's "Dr. Strangelove" again recently. During the first few minutes of the film a narrator describes how during the Cold War, U.S. bombers flew at "fail-safe" points, ready to strike at targets in the Soviet Union. These planes flew 24/7/365 for decades. As my mind was reeling with the calculation of the dollar cost of this madness, it occurred to me that the United States has been continually at war for 70 years, with only the slightest break during the 1990s.
As soon as World War II was over the Cold War with the Soviet Union began (actually you could probably date the start of the Cold War to some time before the end of the Pacific campaign). There were hot wars during the next fifty years, notably Korea and Vietnam, which lulled people into believing there were years of peace, but that was a delusion.
In 1991 with the collapse of the Soviet Union the Cold War came to an end. Silly Americans dreamed of a "peace dividend": the defense budget could be slashed and all that money devoted to education and health and building a more prosperous world. How naive.
The military-industrial complex spent the next decade figuring out how to keep the peace dividend disaster at bay. The breaking apart of Yugoslavia provided a handy justification for military action, and the Iraq no-fly zone kept American jets in the air, but these weren't good enough.
On 9/11 Osama bin Laden provided the perfect excuse to begin another war without end. This one will be better than the Cold War, because the Soviet Union was an opponent that could disappear. Terrorism is a tactic and there is no worries about that disappearing anytime soon.
We naive Americans dream that with the death of bin Laden the war in Afghanistan will end and that peace dividend will finally show up. Fat chance.