Russia (and China) would be only too happy to extend the UN authorization for the US to stay bogged down and bleeding in Iraq.
For Britain or France to oppose a request from the Iraqi government (as opposed to by the US) to extend a US mandate would be politically difficult to justify.
Since the "permanent presence" is a disaster I think granting the Iraqi government's request for an extension of the US presence is the least bad option. It keeps the US bogged down, it frustrates their attempt to declare victory and leave, and it helps the Iraqi government to resist US government pressure. When the capital development of a country becomes a by-product of the activities of a casino, the job is likely to be ill-done. — John M. Keynes
Regardless if victory is declared or not, getting the U.S. to leave is the problem. The current setting is the U.S. will not leave without this nebulous "victory", but once Bush has his "victory" the U.S. won't be leaving either.
As you say, Russia and China are likely to be content with letting the U.S. drive itself into the ground by remaining in Iraq. Europe (France and Britain) can go along with extending the U.N. mandate and still gain the benefit of a U.S. ruining itself.
Regardless of a "victory" moment, the U.S. isn't leaving Iraq.
You know what I'm really afraid of? A scenario in which the US becomes a serial killer of states, causing state failure one country at a time. Failed states don't compete for resources, and the US is safe in North America with two shining seas to protect it from spillover.
It is very easy to bomb a country to the stone age and move on. And another. And another. And on and on. When the capital development of a country becomes a by-product of the activities of a casino, the job is likely to be ill-done. — John M. Keynes