Remembering that this is supposedly a thread about the UN’s self destruction, it seems to me that the Bush administration’s problem is not with the UN generally or even with the Security Council, but specifically with France, Germany and Russia. Germany (I think) lacks a veto, not having been one of the United Nations during WWII, and thus its resistance to a present invasion of Iraq is more embarrassing than critical. France and Russia both have a veto and their opposition is therefore crucial to the building of a coalition under a UN mandate.
Both countries have long pursued a soft policy toward Iraq. You will remember that Russia/the USSR was the primary advocate of a non-settlement resolution of the Iraqi invasion of Kuwait. In the end Russia is more interested in US support or tolerance for its resolution of its internal problems than it is in its trade ties with Iraq. Assuming Russia can be persuaded to live with an American presence on its southern frontier, Russia can be bought off with US non-interference in its suppression of secessionist nationalities and the guarantee of a share of the spoils of an Iraqi war.
France on the other hand has been handed a challenge that it cannot ignore and which is important enough to it that without a substantial retraction of US rhetoric and reassurance about US ambitions France must take an intractable position. France has ambitions in Europe. It is the same ambitions it has entertained since Charlemagne, that is for more than 1000 years. France hopes to be the dominant nation in Europe. This time the vehicle is not the Grand Army but is the European Union. With Germany weakened politically and in economic trouble France is in a position to dominate the EU and to set up the EU as an economic counterbalance to the US. Up until the Bush administration started talking about the Old Europe and the New Europe and signaled an intention to be included in the European economy if not actually in the EU there was a fair chance that France would in the end go along with a war against Iraq. If going along with the US on Iraq threatens French leadership of the EU, France will dump its combined alliance and rivalry with the US in favor of a rivalry only and pursue a steadfast policy of frustrating US objectives.
Can something be done about France? Of course. Like Russia, France can be bought by assurances that the US will not challenge its claim to leadership of an EU that does not include the US. That may be too high a price for the US to pay, especially if French cooperation and UN sanction is not necessary to achieving US objectives in the Middle East.
Plus it’s always more fun to make fun of the French and call them self absorbed ingrates that to make a genuine effort to deal with French aspirations.