So as I said, they have soldiers fighting in three bordering countries. To different degrees yes, but the point is the Iranians have watched them walk into Iraq and topple the government within the last few years. I just don't think you can be so absolutist about it. In a complex government like Iran's, with many power-brokers, policies gain support for a variety of reasons. I'm not disputing their desire to project power, but they've also ramped up the programme significantly since the US invasions of their neighbours. Partly that's because those invasions have massively empowered them (nice going), but it's also no doubt to make sure the same doesn't happen to them. People worry rightly about the Mullahs being unpredictable/irrational, but from their POV you've got Avigdor Lieberman as Israeli foreign secretary, Shas in the government, a strong possibility of a Republican government coming to power in the US in a couple of years with a strong-on-Iran mandate, and who knows, possibly even headed by Sarah Palin. Getting nukes is wholly rational in that position.