It's warped logic, and it is contemptible, but it is understandable - from an emailer to Dean Barnett:

It's simple: If the surge succeeds, then the president, the Republicans and the Democratic supporters won't learn any lessons. In the USA victory only makes you more arrogant. Today Iraq, tomorrow Iran, Thursday Dafur, Friday Pakistan, Sunday Beijing, etc... Success would bring us into a state of perpetual war until we make a truly deadly decision. Making the same mistakes each time.

The emailer suffers from a monumental intellectual hernia, but does likely represent a significant portion of those who positively wish for a U.S. failure in Iraq, and their rationale for doing so.