I googled polls and I think there's a clear majority (roughly 60-70%) that think each of them was a mistake, but there's 25% who don't say that about Vietnam so that's probably a hard floor of psychos that will support any war in any context. That's pretty consistent with the 20% of Democrats and 30% of Republicans who support bombing Agrabah, the fictional country from Alladin.

I'd like to think we don't have a lot of those types on here but if we do they're probably unreachable. But initial support for Iraq was around 80%, so a large number (possibly the majority) of USians followed the trajectory of being lured in by propaganda and then later turning against it, and those people I think are reachable if you can make them realize the same thing is happening again.