An interesting question about the "War on Terrorism": What defines victory?

It's easy to define defeat: If a major American city gets blown away by a terrorist nuclear attack resulting in millions of American dead then we "lost".

What defines "victory" for the Iraqi component of the War on Terrorism? If a stable government is established in Iraq allowing the withdrawal of American troops then that's probably a "victory". However if Baghdad gets blown away 5 years later by an Iranian nuclear strike, would that transform our "victory" into a defeat? One could argue that allowing the Iranians to have the nuclear capability to destroy Baghdad constituted tactical defeat. If we incinerated Iran in retaliation, would that constitute strategic victory? I don't think so. I would argue that true victory for the United States requires that no one gets nuked.

Gary