Seems the FUD on oil and the Iraq war has proven to be quite sticky. Fact is, there are many other oil-rich countries that would have been a hell of a lot easier and convenient to take over than Iraq. Seeing as how the accusation is that the U.S. fabricated a case, it would have been just as easy to fabricate a case against any of them. If I had to plan such a thing, Venezuela would be the first to come to mind, but it's not the only one I would consider.
The war in Iraq was about one thing; Iran. Stabilizing the Middle East by reducing the amount of megalomaniacs by one. By calling Saddam's bluff (which was aimed more at Iran than the U.S.) the coalition slowed down a Middle-East arms race that was just getting started, but was going to speed up quickly once Iraq rebuilt its military capacity. One of the stated goals of the first Gulf War was to reduce their military capability for 10 years. Did the U.S. go about it the right time? Not optimal, but necessary, since it had been roughly 10 years since the first Gulf War. Did the U.S. go about it the right way? Definitely not. Rumsfeld screwed up the war strategy big time, starting with using half the troops that would have been needed for securing the borders. Nation-building and long-term occupation? No thanks; trying to quit.
North Korea presents a decent enough military threat overall, only because they've starved their people in order to pay for their military capability and have thoroughly indoctrinated them into fighting to the death to stay enslaved, but their tension with Japan and South Korea still does not amount to megalomaniac A vs megalomaniac B.