The decrease is particularly acute for the services doing most of the fighting in Iraq: The number of black enlisted soldiers has dropped by 19 percent and the number of black enlisted Marines has fallen by 26 percent in the same period.
Public opinion polls show that the war in Iraq has grown increasingly unpopular with the American people. Opposition to the war among blacks is even stronger.
In the latest CBS News poll, for example, 65 percent of Americans disapproved of the way President Bush is handling the war. That figure dipped to 61 percent among white voters, and shot up to 89 percent among blacks.
Even in the area near Fort Bragg, N.C., where serving in uniform is a family tradition, the drop in Army enlistment by blacks from 2000 to 2005 matches the national average.
Kashonda Leycock is the daughter of a soldier, and the 17-year-old has been a member of the Junior ROTC at Westover High School for more than two years.
She joined to prove to her parents and herself she could do it — not because she wants to join the military. She doesn't. Her primary objection is the war in Iraq.
"Why are we fighting?" Leycock asked. "Nobody has really said why the war is still going on. I don't think it should be going on because it's not solving anything. ... None of my people want to go there."
The lack of support for the war by blacks — in uniform or not — is striking. A poll of Cumberland County residents, commissioned last year by The Fayetteville Observer, showed that 69 percent of whites said the war in Iraq was worth the costs. Only 19 percent of blacks agreed.
The survey, conducted between March 31 and April 18, found that 71 percent of whites with military ties believed the Iraq war was worth fighting, but only 21 percent of blacks with military ties.
Curtis Gilroy, who works on recruiting issues for the Department of Defense, said that sentiment has been noticed nationwide — and with concern.
"We want to make sure all recruits see the military as a viable career option. But we also understand the reservations that individuals might have," he said.
He noted the influence of adults such as parents, teachers and ministers on young people — and how their opposition to the war would make them less likely to recommend a military career.
"Mothers, in particular within the black community, play a more prominent role and are far less likely to recommend military service," Gilroy said.
Despite the declines, the percentage of blacks in the military continues to exceed the percentage in the U.S. population. Nineteen percent of the military's active-duty enlisted force is black, compared to 13 percent of the country's population.
And there are young black people who do see that career option, despite or even because of the Iraq war.
Tyrell Rembert, a Westover senior, is a private in the North Carolina Army National Guard. He joined in April 2004 at the age of 17, picking the Guard over active duty so he could begin training before graduation.
He said he joined because he knows people who have served and are serving in Iraq.
"I wanted to be able to help them out, I guess you'd say," he said.