That appeasement argument doesn't hold the road.

First, the coalition of the willing has been manipulated by the white house administration WMDs claims and the spaniards by their own prime minister urge to accuse another terrorist group.
Second, nobody forgets that the war in Iraq was started by the US and the countries willing to follow it. The UN was in Iraq precisely to prevent a war and it didn't work because the US would not trust the UN even though the UN is now vindicated by the lack of WMDs.

Appeasement is for those who are being invaded, or threatened to be invaded, not the invader.

The fight against terrorists is a totally different matter as their way of fighting consists in avoiding troops, hiding for a long time and using the hatred born through the behavior of the troops.
France and Germany are a much bigger help in that matter than the UK, as it's about secret services, intelligence, infiltration, essentially using the same weapons they have.

Raoul