Who the hell are "they"? Nobody is born a jihadi, they're the teenage punks of their respective nation, and by meddling in their business we're making a target of ourselves, as westerners.
Just take Mubarak as an example, how do you think egyptian teenagers feel about the US? They've been beaten by corrupt police backed by the corrupt government which has been backed by different forms of US aid.
It doesn't matter why Mubarak was supported. The fact is that people who don't even dare to dream to have just one of the rights listed in the BOR have been beaten, killed and incarcerated by a corrupt totalitarian government backed by american tax dollars.
They will be bitter as heck and when the islamists get their hand on them they become fuel for the jihad.
Edit: For people who aren't guerillas the US soldiers pose no threat, they can't intimidate them. What about all the angered young men in the middle east who are not iraqi or afghani? At least two generations of egyptians consider the US a dictator supporting, reckless and ignorant beast. From their perspective, that is what the US is. They don't know about the second amendment, they don't see how one terrorist attack on the US equates to two wars in the middle east. They have bombs going off all the time. I've met an Egyptian who lost an eye to a terrorist attack by some islamist nutjob. He thought the islamists were crazy people and he hated his freedom hating government (that was paid for by US dollars).
We all hate the jihadists, but the issue at hand is to keep their numbers from growing! The vast majority of the people in this part of the world just wants to buy a house and a car.
Step on one and another craws out of a different hole.
If Israel has "flattened" any neighborhoods - besides attacks taking out observed rockets, weapons and Hamas leaders' homes - there's more to the story than DU folk are saying (or, probably, know):