Juan Cole raises the interesting scenario in which the guerillas continue to attack non-US forces over the next couple of months.
Most of the international units are committed to Iraq for no more than a year. It is an extremely expensive step diplomatically for a second tier national leader to pull their battalion or their brigade out of Iraq short of it being destroyed in combat. However it is much easier diplomatically and politically popular for a country to be unable and unwilling to send a replacement contigent.
At my blog I have examined this issue in greater depth. Right now the US has 18 brigades of Americans, 1 British and 4 international brigades deployed to Iraq. The US wants to draw its forces down and by next spring, it intends to have no more than 16 brigades in the country plus the international contribution.
However if two or three of the international brigades are not replaced, then the US is up the creek as there are no more mobilized reserves available for active duty in Baghdad on April 1, 2004.
This realization has led me to give much further credence to the Bush Bugout and Declare Victory talk that has gone on around here. It makes sense as the US continues to see the correlation of forces work its way against the interests of the United States.