Even if you remove the domestic partisan posturing from the story, you can see President Bush is doing some fuzzy math in his Iraq strategy, says Peter Beinart in The New Republic:

European opposition is a problem financially and politically. It's a financial problem because when it comes to overseas expenditures, the United States (especially with Republicans running the government) is cheap. If Europe doesn't back the war, it won't be obligated to help pay for the post-Saddam peace. And that could leave Iraq's reconstruction (including, perhaps, peacekeeping) almost entirely in the hands of a Bush administration that loathes nation-building and faces a mountain of budgetary red ink. In which case Iraq might never be adequately reconstructed at all. European opposition also represents a political problem because much of the world--rightly or wrongly--considers the United States a colossus bent on dominating the planet. If war with Iraq is seen as a purely American exercise, it will provoke even greater hostility toward the United States down the road. The Bush administration seems to think multilateralism gives weak European states an influence they don't deserve. But it also eases their resentment of the United States, which makes them less likely to band together to try to cut Washington down to size.