It's always been about the post-war dispensation hasn't it? The global coalition against the war was largely gathered around this concern -- from fears of terrorist attacks to an outright anti-imperialist understanding of the meaning of this war. This is/was not a popular regime, and there's not about to be a quiet, determined popular resistance as with Vietnam. Indeed, it's probable that there isn't even the level of popular resistance as in Afghanistan which evidently is now re-grouping. [Even if you don't like it, that's not to say that it isn't popular]
The terrorist attacks may not materialise, although the hatred of the US is probably at its highest point and with considerably less tension and ambiguity than previously. The imperialist dispensation I take as a foregone event, but also as an imperialist quagmire, especially now, with both the unilateralness of the war as well as the determination of Washington (to the dismay of Whitehall, apparently) to carry on in that unilateral path -- for which we have to thank the ideologues.
So, the point is to pay attention to what happens afterwards, and to make sure that this is kept in the public eye. Perhaps more than any other group of people, Americans are best placed to undertake this surveillance and to make this information available.
It's been disheartening to note that Afghanistan has essentially fallen out of sight, except for snippets here and there. For instance, I picked up a one liner about infant mortality rates there being higher in 2002 than in 2001 from a photo caption in the NYT. I picked up something else about 'assisted return' in 2002 and the impact of that.
It's also to anticipate the next war -- and I think there's little doubt there will be another. It's also to monitor the orientation on China, for if that came to a war, god help us all; not because Beijing wants a fight, but the ideologues in Washington appear to view Beijing as the likely challenger, and this war (and Japan's craven support for it) will likely boost China's centrality in E Asia.
We are, as the old Chinese phrase has it, living in "interesting times", meaning times fraught with danger, but also opportunity.