I think you are greatly underestimating or at least greatly under-appreciating the role of USA defense on the world stage. Why do you think EU and other USA allies can get away with spending so little on defense? They are basically outsourcing defense and weapons development to us. F-35 development went way over budget, but actually making one now is relatively cheap and will continue to get cheaper - cheap enough that an ally like Israel could purchase a dozen as a part of their smaller defense budget in the coming decades like they currently do with F-16s. Why is the global shipping industry so much lower risk that it was in decades past? The US Navy protecting shipping lanes is largely to thank.
I'm sure US DoD is worthy of many of its criticisms, including high budget, but it irks me to see the baby so eagerly thrown out with the bathwater at every opportunity.