Use the argument of Soviet Union in Afghanistan, explain, that 9/11 was planned by Afghanistan, yet after Russians pulled out of Afghanistan they were not followed by angry terrorists and were not killed. Thus you have no ground to be worried about sweet revenge, sure they(Iraqis, terrorists etc.) will have their moment of defeating Superpower but it will not last for too long and humiliation will not really take place. So neocons need to calm the fuck down and put their pride somewhere distant for a while.