it just comes down to whether you believe the us government or not. Those that preach the oil reason have a large distrust of the government. #1 is valid in the light of 9/11 in the fear that not doing something pre emptive will be disasterous later. Proponents are those who believe the US is a just country with just leaders #2 is valid in the light of a us conspiracy to control the world. Proponents are those who are against the US. It's really simple, who do you trust as your valid source of information. It is hard to convince someone who believes that the government is truthful, when there have been lies in the past. What I find interesting is how these same people are able to find the good in the most evil of people, yet are unable to see any good in generally good people.
The problem with #2 is that it will happen. Iraq's oil will be sold on the market, and whoever sets up the initial government will of course get preferential treatment. There are very few companies with the expertise to build the infrastructure for oil, so of course you can blame the west. To prove that this is not the case for war is hard since it will happen, I believe, yet the same argument can be made for #1. Iraqis will live better lives just as before the Saddam regime as well as Americans.
Attacking North Korea is ludicrous, if the idea is for the safety of the American public. You're looking at hundreds of thousands of deaths on the American side, and possible a million on the North Korean side. This is not an acceptable solution, since the current situation is better.
The debate should be whether we go to war no on the grounds of oil, but whether a war will cause a lot of human suffering and deaths. I believe in more mainstream circles, this is the case in the mainstream media. A war could possible kill many US soldiers and perhaps Israel might enter which opens another bag of problems, as well as massive civilian casualties due to Saddam's placement of targets. These possibilities should be the reasons for not going to war, not the threat of controlling the oil.