The worldwide US military presence has a suppressive effect on wars; I'm confident south-east Asia would have been in multiple wars since WW2 if it wasn't for US presence, and Russia would've tried to take back its former soviet countries if it wasn't for NATO which is mostly the US's $2T army.
And I don't think the US has had to deploy its full capacity for a long time, not even Iraq / Afghanistan. That's more of a logistics issue though, they could've multiplied their forces and materials but it wouldn't be any more beneficial.
And I don't think the US has had to deploy its full capacity for a long time, not even Iraq / Afghanistan. That's more of a logistics issue though, they could've multiplied their forces and materials but it wouldn't be any more beneficial.