But at least 34 other countries are expected to contribute 15,000 to 20,000 troops to the effort in the next several weeks, American officials say.
Thus all other nations might contribute 20,000 troops at most.
Contributing 4,000 troops is not beyond the means, or the interests, of America as a great power.
As of March 2008, 113 countries were contributing a total 88,862 military observers, police, and troops.
American officials say they are not asking other countries to contribute troops to an invasion.
Nor would it contribute troops to the peacekeeping effort on the ground.
Both sides in the conflict will contribute troops to an integrated force.
It contributed 20,000 troops to the coalition fighting the gulf war in 1991.
In addition, allied nations will be invited to contribute troops.
But for the rotation plan to work in the long term, the general said, allies must contribute more troops.