Well the “Hell no side” can point to the Mesopotamian Adventure of the New Millenium.
On the other hand, in 1991, the Iraqi Army had been absolutely mauled, this was not the case in 2003, where it just more or less melted away and many soldiers and officers became the initial focus of the resistance. In 1991, they would have been less willing to so melt away.
There is the diplomatic issue to consider true, but on the flip side in 1991 nearly everyone thought Iraq was in the wrong, Syria sent forces. In 2003, you had massive protests worldwide, so I submit that diplomatic opposition could have been overcome, especially if the excuse used was that “no authority exists in Iraq” or something similar.
Moreover unlike 2003, there was no shortage of troops, the US alone had half a million men (incidentally the amount that Shinseki thought was need the second time around) so the failures of 2003, which were caused so much by the paucity of manpower might not occur.
Flip side, the Iraqi Army might actually be a bit more motivated to fight defending their country…, and this time there were WMD’s. Historically, the SCUD regiments were the only parts of the Iraqi Armed Forces which actually delivered, the lack of damage caused was due to the flaws in the extended range SCUDS, not due to anything wrong with the men, and while we are at it, here they are using shorter and more accurate systems.
Would Cheney, Powell et al, mess this up as badly as…Cheney, Powell:D
This OP does not consider the morality of the question, just the feasibility and please limit your discussion to that, thank you.