no. because iran won't invade iraq; what does iran have to gain?
if this happened, israel would probably get involved. when israel gets involved, the rest of the west gets involved. and btw, israel, ALWAYS wins, and I'm not citing biblical stuff, it just does, because it has military superiority in the region.
now we know that the USA is the second most powerful nation in the world, militarially, barring only china, where their standing military is something close to the population of the USA. still, we're better armed than china, so in the event of war, we would probably win-- although our economy would initially colapse, though, it would get better, very quickly, and stronger than before.
now, in your hypothetical war, china is not likely to get involved, so the major countries are the USA, Israel, Saudi Arabia and The UK.
it ought to be the aforementioned against Iran.
iran invades iraq, the USA would declare war on Iran, Israel would declare war on iran, the UK would declare war on iran, and if memory serves, about half of the EU would declare war on Iran. and saudi arabia declares war on iran--what happens? iran go boom. and they get a new government. the major problem? the president of iran is almost as crazy as bush-- but twice as shrewd.
now, if he starts a ww3 I can't see how it would benifit him, unless there's more going on here than meets the eye.
as for bush? starting ww3 would make him very rich indeed.
so I think we need some major power limitations from congress. time to tie his hands down.