Yes, and in all three cases, Japan, Germany and South Korea, we established a democratic government after subduing a militant global threat.
Iraq is proving to be messy, the advent of a terrorist underground adds a new twist, but the desire of the people to be free and to vote...HOPEFULLY...will bring a new way of life to Iraq.
The biggest difference in Iraq as compared to the others is that the other cases each involved a society that was primarily one ethnicity. In Iraq, not only do you have different ethnic groups, but even within the same ethnic group, you have dominant and aggressive rival religios sects.
This isn't to say that it can't be done, of course. It's just pointing out that it will likely be more difficult.