I wish humanity didn't need a military but saying the world's largest military doesn't give anything back is a bit misleading. Some would argue the world's largest military enable the post WW2 order and with it the free trade that most of the world depends on. So in a very concrete way, the American tax payer subsidizes much of the world's economy.
Now in a post cold war with the growing isolationist tendencies of Americans, this may require most of the world, namely western europe to start paying for their own physical security.
Now in a post cold war with the growing isolationist tendencies of Americans, this may require most of the world, namely western europe to start paying for their own physical security.