Put a Marxist in the White House, and the Americans WILL run away and Iran takes over. Not a pretty site.
I think you have hit upon the Iranian strategy. Do not provoke, keep the US bogged down in Iraq and wait for the war weary American public to elect a socialist Presisident, who will run and pay the jizya rather than fight. After that, it is just a step by step process to building an Islamic superpower.