As member nations consider another calendar year in Iraq, the Bush administration's "coalition of the willing" appears increasingly unwilling to commit to the cause indefinitely.
Last week, two countries finished withdrawing the last of their troops from Iraq, and two others decided to cut their forces by about a third. In all, the coalition has declined from a 2003 high of 38 nations and 50,000 troops to 28 nations and about 20,000 soldiers today.
In terms of military operations on the ground, the withdrawals mean little, analysts say. Only Britain has a substantial security role, and so far it has remained steadfast. Yet each country's commitment to Iraq - however small - is a significant token to an administration that has long sought global support for the conflict. As such, the continual reshaping of the coalition is more a matter of foreign policy than military power, as Washington takes account of its strongest allies in the war on terror.
"Iraq has been the crucible that has shown us how limited our cold-war alliances were," says Thomas Donnelly, an analyst at the American Enterprise Institute here. "It took us 50 years to build NATO; the challenge we have now is that we've got to come up with something new."
The coalition is perhaps the first sketch of that new security structure, but recent months in particular have altered the face of it. Bulgaria and Ukraine withdrew the last of their roughly 1,200 troops from Iraq last month. Last week, Poland announced it would remove 600 of its 1,500 troops by March, and the South Korean parliament voted to pull out 1,000 of its 3,200 soldiers - with the rest leaving next year.
The news comes as the coalition was already shrinking. Italy will withdraw 300 of its 2,800 troops this month as part of a phased pullout, and other nations - most notably Spain and the Netherlands - have already withdrawn either all or virtually all their troops.
So far, the Pentagon has looked at the fluctuations without great consternation. "We don't set any conditions on coalition members," says Lt. Col. Barry Venable, a spokesman. "Certainly, we'd like more, but we're grateful for what each and every nation feels it can contribute."
The ambivalence is born of the fact that - with the exception of Britain - coalition nations have not done the heavy lifting of fighting insurgents. "They weren't going to win the war, and if they left tomorrow, they wouldn't lose the war," says Andrew Bacevich, a professor of international relations at Boston University.
Drawing conclusions from who has drawn down their forces and why, however, is difficult. For its part, Italy says its withdrawal is part of a "success strategy." Even the United States has announced plans to cut troop levels, with military leaders saying they see progress in Iraq, so it is hardly surprising that other nations would be eager to do the same.
Yet analysts suggest there are a host of other reasons, as well. In some cases, such as South Korea, relations with the US have soured, giving the country less incentive to stay. In others, such as Spain, voters turned so strongly against the war after the Madrid train bombings that they elected a government that pledged to withdraw from Iraq.
In this context, continued participation in the coalition is an important measuring stick - both for how influential Washington remains, and for who is willing to listen. And the Bush administration has stressed how much it values any help. The president stopped in Mongolia in November to thank the country for its 130 soldiers.
Indeed, among the limited contributions of coalition nations, some have a significance beyond numbers. Poland has become a major power broker for the US in Europe, and its decision last week to keep some troops in Iraq - it had previously planned to withdraw them all - was seen as a US foreign-policy victory. Moreover, Iraq marks the first time that Japan has deployed troops to a war zone since World War II. Though the troops are there on a humanitarian mission, the US has encouraged Japanese military participation as it seeks a counterweight to China and South Korea.
"It marks a huge threshold for Japanese domestic political opinion," says Mr. Donnelly. "Japan used Iraq to rethink its whole approach to the use of military force."
From the beginning, however, international support for the war in Iraq has been thin - even among coalition members - and it has become only more so. The US also did most of the heavy lifting during the first Gulf War, but then it had a huge array of allies to help pay the cost. Though the lessons of this war are tied to its uncertain outcome, they have pointed to the limits of a limited coalition.
"What we need if we intend to have this global war on terror include some additional military campaigns is substantive military participation by allies and money," says Dr. Bacevich. "A coalition matters to the degree that it brings something substantive to the table."