Gosh, Raoul gets this one almost right. 1441 does not by itself authorise force. 1441 is seen as strengthening earlier resolutions- sort of "bringing up to date" the other resolution, and etc.
Before going to the Security Council, the US made it very clear that it did not need the UN or another nation to agree with it's position that it had the legal right to use force in regards to Iraq. The US was willing to do this alone, IF neccessary.
Many argued and still think that it would would a wiser course to avoid going through the UN. No other country goes through the UN. Why, try to establish this precedant- it will only weaken the US ability to defend it's national security in the future.
That was basically the argument, but it's not the argument I favor. I was not against the idea, because I thought it was illegal, but I saw it as a good thing to try to strengthen this precedent [even though the French action in one way weaken using this appoarch- and there is a possiblity that the French did not want this precedent strengthened because it would weaken there ability for taking future unilateral miltary action].
I think that going through the UN was a risk worth taking and that even when the French did the predictable course of threaten to veto no matter what, it was still worth going through the UN.

Now, an example of how exactly the French fucked this up, is what Russia is doing right now. The Russian are declaring that they have this right of acting unilaterally in order to defend their nation security- and of course they do have this right. Had the UN worked with the US, the most likely thing Russia would be doing now is not declaring this right but instead be focusing on using the UN as a means of resolving it's national security issues.