To dramatically oversimplify, the local, popular political will for American military intervention anywhere else is based on one of three things. Bravado - America is the best, and it's up to us to make the world a safer place. Justice - Those sons of bitches need to be struck down for the good of everyone else. Greed - We need this stuff, so it's an act of necessity, not violence. At the policy level, a lot of the people with authority have a dangerous love of making "the hard choices"; there's a certain tough guy-ism that a lot of advisors and politicians aspire to, in which they work very hard to justify monstrous human costs by finding a metric that makes it look rational. There's a certain kind of mind that decides propping up a dictator is the morally correct thing to do, and calls it "realism"; they're a lot less vocal and a lot less obnoxious than they were during, say, the Cold War, but the same sort of thinking applies.
I'm a pragmatist at heart, so I agree that on this scale the ends often justify the means, but there's a fair bit of willful ignorance about what the ends actually are; instead what apparently matters is justifying the means already decided on.
But that is just my tangent about one of the things that is Wrong With America, and shouldn't be taken too seriously. It's never really that simple. The point is, there's no actual political impetus to solve problems in the region - the political will is there for a dramatic overthrow of a villainous tyrant, but most of the voting population isn't motivated by problem-solving. They're motivated by things that make them feel the world is Right. So if we wanted to, I don't know, install a puppet dictator we actually controlled and forced to implement gradual democratic reforms that transition a given nation, it isn't going to happen. It's expensive, it's boring, it's slow, it requires constant attention, and most importantly it feels Wrong - and quite frankly it probably is wrong from a pragmatic point of view, but I do not have the time, energy, or resources to design a workable Middle East policy from the ground up in my spare time for the purpose of making a forum post. So consider it an arbitrary example.
But there is no solution that satisfies the constraints of the real political arrangements we have to deal with, and so sadly we're waffling along with what is the best we can do. And that's probably the most depressing part of it - our fuckups have caused so many problems, but if we ever stopped fucking up it would get so much worse, because it's already too fucked up to let go. We gotta keep sinking these costs, because the alternative is a cost in human lives and rights that we aren't willing to pay.