At one time, these forces could be justified as a counterweight to the Soviet Union, but the Cold War is ancient history. The Korean War ended in 1953, yet 28,500 American troops remain in South Korea.
Going over the fiscal cliff may not be good for the economy, but it might have one valuable result: forcing Americans to reassess our enormous defense budget.
Taking $492 billion away from the Pentagon over the next decade wouldn't be hard to do if we forced other nations to take more responsibility for their own defense—and used the opportunity to reduce our overall troop strength. What's hard, and expensive, is our vast array of overseas commitments.