Also seems that having a very capable military that lets you project power around the world also invites that power to be used. See for instance the Iran war. Quite pointless by all accounts and wouldn't have happened if the US didn't have aircraft carriers to send around the world.
So perhaps thriftiness in defense spending would also invite a prioritization in actual defensive capabilities?
Even in a hypothetical situation where the USA had no aircraft carriers our military probably would have conducted some raids to delay Iran building nuclear weapons. The initial strikes against nuclear facilities were done with B-2 bombers launched from Missouri.
> Also seems that having a very capable military that lets you project power around the world also invites that power to be used.
I assure you that is a much better problem than the alternative.
I think the likely result would be more war. It wouldn't be with america, but without anerica providing protection to its allies in the region, the various countries in the region would probably be emboldened to fight it out themselves (im assuming in this scenario that russia and other great powers are also incapable of force projection. Obviously russia is busy right now, but historically they were knee deep in the middle east and much of us involvement now is a legacy of the cold war)