And the minute North Korea uses a nuke against Japan, Australia, or the Western U.S., then it's Bush's fault for not invading North Korea when he had the chance.
And that would be entirely correct. North Korea has been a much more dangerous threat than Saddam's Iraq for a while. Its army could march on an important trade partner, risking some 20-30K American servicemens' lives in the process. Add in nukes and America had a real reason to get involved. Iraq's ties to terrorists were at best nominal compared to NK and Iran. Hell, Saudi Arabia was a more legitimate target after 9-11 than Iraq because the Saudis financed Al Qaida and made it possible for the destruction on our soil.
You don't have to be a lefty to legitimately oppose the invasion of Iraq. It's common sense that Iran and North Korea were and are more dire threats today than Iraq was.