But... if the US stopped its noble endeavor of spreading democracy and freeing people from the Evil, who else would do it?!?

I'm one of those millions you've mentioned who believes that the US should not be the World Police any more and the enormous amounts of money wasted on foreign military operations would allow our science and economy flourish. The amounts spent on the foreign wars are mind blowing. A couple or percent of the military spending would buy each US citizen top level health care. Another couple percent: outstanding free education, another few percent new energy sources, space research and there would still be money left. The cost of one missile fired from a fighter jet could take a bunch of kids through college. We could have had space and Moon stations, robots, artificial harts and limbs and flying cars and what not by now if we didn't blow (literally) billions in foreign wars that caused nothing but misery, suffering and loss.

The US should still maintain a network of intelligence operatives just to know what's going on out there. But our troops could serve much more useful purposes as you have mentioned.

This way the US would have much more money to solve its own internal problems and could still offer peaceful support and humanitarian relief to those who need it. And I bet in the long run that would gain us more respect from other countries than blowing the sh1t out of them.

The US foreign policy is causing irreversible damage to the country itself, but hey.... it makes the corporations rich and that's all that matters, right? And Americans are too dumb and too busy trying to keep their credit score in good standing to notice and to care.

Although, the same corporations could still prosper in a world without wars. But our leaders have insatiable hunger for power and domination and that always leads to wars.