News flash for Tom - it's not 1945 any more.
Did you ever pause to think that much of the load involved in the "heavy lifting" the US is doing has been brought onto itself?
And if you want to be the biggest and most powerful, you have to expect to carry your share anyway - look at the stats of per capita losses in WWII. Don't put down smaller nations just because they are smaller. Or because they have different priorities. You can imagine scenarios all you like - and you do have a talent for that - but imagination isn't reality, and your hindsight predictions of world disaster if not for the US are impossible to prove.