The author mentions "perverse" incentives in Congress, but what he doesn't mention (because it's a very politically difficult subject) is the perverse incentives afforded military officers. When you have a system in which it's so common as to be expected that the officers who influence your purchasing will in a couple years retire into a job with the private contractor from whom you're purchasing, you have a recipe f…
The basic perversity is building a gigantic military in peacetime because the arms companies have enormous lobbying power. Everything else flows from and is secondary to that.
Have you considered the gigantic military requirements that are placed on the United States? By treaty alone, the US is required to defend almost all of Europe, Japan, and South Korea. These are not easy requirements to disentangle from; if Japan alone were allowed and required to rearm, it could lead to an arms race that would destabilize all of East Asia and either stall or undo the tremendous economic gains that have been achieved in that region. If it wasn't for US obligations towards NATO, most of Eastern Europe would suffer the same fate that Ukraine is facing from Russia. If it wasn't for the US Navy enforcing freedom of navigation (http://en.wikipedia.org/wiki/Freedom_of_navigation#United_St...), tinpot dictators could shut down international trade by making and enforcing illegal claims on international waters.
Maintaining the Pax Americana is a hard, unappreciated task.