The question is moot. The political capital for invasion has been spent, and as we have hopefully learned (for this generation, because collective memories are short) that invading a country is easy. It's what you do with it afterward that's difficult.
We invade-> depose leadership-> power vacuum ensues-> armed struggle ensues-> etc etc etc. So we then leave with the country in chaos?
How many of these scenarios can we afford per administration? We have two right now, where one (Afghanistan) would have been plenty.
Now from a philosophical POV, IF the people as a whole want the US to intercede, and the situation is desperate then I'm not against it. Considering how politicians pick criminals like Chalabi to represent citizens viewpoints, I can't believe anything I'm told when invasion is mention.
Cliffs- Theoretically yes on rare occasions. Practically speaking, no.