I agree invading Iran would unite the Iranian people under the current regime.
Also Iraq was a bad choice, but attacking Afghanistan was fully legitimate. Sure the end result did not turn out well as the Taliban are still powerful, but Al Qaeda's abilities have been diminished.
I agree that we should have used more Drone based attacks in Pakistan from the get go as Obama has done.
Also I expect great turmoil in Iran in the next election after the results of the Arab Spring.