Well, you have been meddling in their affairs since around the World Wars if not earlier. So did assorted European states, mind you, the main difference being that they quit...

A good part of the crappy leadership there hold their posts largely because they made convenient allies for the US (and/or the Soviets) at one point or another, or alternatively deposed some such ally who'd managed to alienate his subjects (*coughshahcough*).

Do I really have to remind you where the Iranian Revolution came from...?