[pessimizer]

I don't think the answer is any deeper than that wars involve spending an enormous amount of money on contractors, and those contractors in turn fund politicians who will drive more business in their directions, then supply then with output from thinktanks that they fund to justify those decisions to their peers and the public, and ex-employees to hire into the bureaucracy. This, they do in a completely bipartisan manner, so their papers and bureaucrats are installed permanently, not turned over between administrations.

It's not a single-minded conspiracy with some deep reason. It's just basic economic incentives. There's nobody in the US who will make money from not attacking the middle east, and plenty that would. Policy in the US is determined by financial interest.