The GOP wants the public to forget that Republicans got America into a disastrous, unnecessary war, of course. But the larger problem is that conservatives simply have not acknowledged the failure they unleashed in Iraq, let alone learned from it. To judge both from Mitt Romney’s rhetoric and his advisors’ track records, when it comes to foreign policy, a Romney administration would be a second Bush administration.
Often critics of the Iraq war write as if it was self-evidently a mistake and that the Republican party establishment will somehow be forced to come to grips with it. Certainly, a majority of the American public thinks the Iraq war was a mistake, but what they think really doesn't matter that much (it could, potentially, if Congress asserted a more active role in these matters, but that's not something they care to do). The truth is that the Iraq war is slipping (if it hasn't already) the bounds of objective reality and entering a realm of partisan positioning.
Many of those advising and supporting Governor Romney's campaign not only think the war was the right thing to do, they think it was largely a success. Furthermore, because the Democrats have, brazenly, evaded their share of responsibility for voting for and endorsing the Iraq war, and have instead painted themselves as the war's skeptics and critics (which, to be fair, some were from the outset) they have reinforced a Republican tendency to circle the wagons on Iraq.
So it's no surprise that Romney and his advisers won't offer a mea culpa for Iraq, since they don't believe it was wrong and because such an admission would invite negative political consequences.
This leaves us with one political faction that believes the lesson of the Iraq war was that it was a good idea and something to replicate in the future - likely with Iran, and another that doesn't have a strong position one way or another but will gladly tack in whatever direction political expediency points to.
Ordinarily you'd be forced to conclude that no superpower could continue in this manner for very long, but when most of your potential challengers are equally dysfunctional (or even more dysfunctional), there's really little external pressure to get your act together.