Now that that picture's out of the way, back on topic (or at least close too it).
The US of A cannot be the world police. It didn't work in Iraq, it didn't work anywhere else, in fact, and it won't ever work.
That said, States citizens CAN help other people. It just doesn't work well on a global scale.
I say, (and I should clarify that I am an States citizen) the US should get rid of the aircraft carriers, the international array of bases, the missile silos. Arrange the military as a solely defensive system with only two offensive groups; remote attacks, which use telepresence drones and such to allow engaging things on a military level externally when necessary, and a small fund of a couple billion dollars to keep a couple of guys named Vito on hand for the small stuff.
Those three departments, taken together, would cost a tiny fraction of what we have now, and would leave all the citizens of other countries without our overbearing presence.
Some people would say that the overnight disappearance of the military-industrial complex would ruin the economy. What would they say to a tax reduction for everyone of nearly all of the military's budget, and the remaining 10% or 20% being split to education, infrastructure, and dept reduction. When we sell off the massive quantities of military infrastructure, we'll put most of that money into paying off the dept too.
And where would we get all our protection from? How would we keep the USA's enemies away? Well, as far as I can tell, the only thing that people really hate about the US is it's invasive preemptive attacks. So if we have a tiny, purely defensive military, well, there goes that problem. Nobody's going to invade us for our resources- those are gone. There are no idealistic threats that a military has any chance of fighting (Seeing as the insurgent population of Iraq and Afghanistan has most likely only gone up in the time we've been there), so we aren't getting weaker, and maybe 5% or 6% of that formerly military spending can be sent over to the intelligence and police groups who's job it is to actually solve those sorts of problems.