The reason to invade Iraq is nowhere near substantial when looking at the definitive situation. However, I will say this... I still believe that the U.S. and Britain thought that a democratic Iraq would against Iran in the long run. Had Saddam Hussein still been in power... the possibility of a joint Iran/Iraq attack on their common enemy, Israel, was very likely. I'm rather glad that there is no Hussein to ally himself with Ahmadinejad .