The point of imperial declines lasting a long time is valid - indeed, one could argue that remnants of the Roman empire still manage to exist to this day (in the form of Italy partially, and the Vatican certainly).
(so far i haven't heard one {and i'm not holding my breath})
What, you mean you doubt the just reasons for this war?
Like the chemical weapons Saddam has, and would certainly use on the US forces? Or, er...wait....troops 50 miles from Baghdad and still haven't found any chemical weapons. Hmmmm....
OH, wait! Iraq not disarming! Yeah, that's the ticket! All those scuds they didn't destroy! Except...no...wait....they don't have any anymore?
Hey! How about how cruel Saddam is to his own people!! Yeah, there you go! We are liberating the oppressed Iraqis! Just like we liberate all equally oppressed citizens, like those in Pakistan, Saudi Arabia, Turkey, Kuwait....er....nevermind.
But, hey, this war certainly isn't about oil or American imperialism. Otherwise, you'd see things happening like US troops taking protectice custody of Iraqi oil fields, the Vice President's former employer being given contracts to rebuild Iraqi oil wells, and in all cases of contracts awarded to 'rebuild' parts of Iraq awarded to US companies.