So I'm a little confused at how the current administration couldn't have predicted that Iran would get involved with the regime change in Iraq. Consider that:

a. Iran is run by a motivated Shi'ite government that's been agitating for Islamic rule in the region for decades.
b. Iraq has a Shi'ite majority that's been oppressed by Iraq for decades.

I suppose the administration is more surprised by the speed of things than the actual occurance, but did they expect that Iran was sitting quietly by, not building connections with Shi'ites in Iraq? It's this sort of thing that further suggests that we may not be the best group of people to muddle around in the Middle East.

I would also point out that just as Tom Clancy played Nostradamus in Debt of Honor with the use of a commerical airliner as terror weapon, he may have presaged the current situation in Iraq in Executive Orders, where the assassination of Saddam leads to Iranian intervention in Iraq and the formation of a combined Islamic state. In the book Iran had to get rid of the ruling generals first, giving them all assistance in getting out of the country. Given that the US military has performed this role in real life, perhaps Iran will find the formation of a United Islamic Republic easier in real life than in books. If the president of Turkmenistan dies in a suspicious car crash, I'm moving to a cabin in the north woods of Quebec.