It goes back further than recent dictators. The US and UK sponsored a coup to overthrow Mossadegh in Iran in 50s. It was over oil, funnily enough. That led to the Shah, and in response an islamic theocracy overthrew the Shah in the 70s. Meantime, the US backed the Mujahideen in Afghanistan, because islamic freedom fighters were better than Ruskie Commies. They became Al Qaeda. Then the US best friend in the region, Saddam gets wrongly blamed for 9/11, but only after the US got all the Saudi royals safely out of the US, even though he was a foe of Al Qaeda, and non-existent WMDs, so a war is started which kills tens of thousand of people and destabilises the precarious balance with Iran even further. Now Saddam was undoubtedly an evil tyrant, but there have been quite a few of those around that the US did not start wars with. So Iran starts to develop nukes, in response to their perception of the threat from Israel, and everyone goes crazy. Not about Israel's nukes, of course, because we all pretend those don't exist. Oh, and the UK and US were instrumental in the foundation of Israel too, and who would have thought a Jewish state in the area would cause problems?
The west seems to cause a bigger problem every time it gets involved, so it should step out. Let other local states which have the capability, do the heavy lifting this time. Give them diplomatic and strategic support, but otherwise leave this as a regional issue. If the wets is really concerned about beheadings of innocent people, Saudi does far more of those, so when does that invasion begin?
yep, Oils has a big part in this as you say.