Well, at least someone is willing to offer some specific scenarios.
Radical Islam is not a country. It is a variety of terrorist organizations that don't require a large conventional infrastructure to respond to them. Do we really need over 200 stateside military bases to combat radical Islam? We obviously need a few for rapid response forces, but the level of redundancy is absurd.
You also mention a land war on the Korean peninsula. This is no longer 1950, when South Korea was actually smaller in population than North Korea. It is now three times larger, and is perfectly capable of defending itself in any conventional land war. In any case, the US force there is only about 30,000 and serves mainly as a tripwire deterrent. The massive U.S. military spending we still see today is not due to the North Korean threat.
So, still waiting for someone to explain where the threats exist in the modern world. As someone who lectured at Yongshan University in China on security studies, I met many Chinese military analysts, and every one of them was befuddled at how the US could see China as a threat in any meaningful sense, given the massive asymmetry between US and Chinese military power. The same thing with Russia, which used to be an enormous military power with a population of over 300 million plus satellite countries of another 100 million, and is now just a shriveled shell of its former self, with a population smaller than Bangladesh and military strength largely dependent on its aging nuclear capability.
There has to be a better argument for why U.S. per capita military spending is actually higher today than it was at the end of the Cold War? But I have yet to hear it.
