With about 20,000 U.S. Marines engaged in a “tough fight” against insurgents in Afghanistan, lifting the “don’t ask, don’t tell” ban on openly gay soldiers serving in the military is a bad idea, General James Amos, the new commandant of the Marine Corps, said Saturday. Amos, who assumed the commandant position two weeks ago, told a bevy of San Diego reporters that allowing homosexual service members could hurt unit cohesion and combat readiness. “There's risk involved,” said Amos. “I'm trying to determine how to measure that risk. This is not a social thing. This is combat effectiveness.” Amos, who is currently reviewing the results of a poll military members and their families took about the effects of lifting “don’t ask, don’t tell,” believes that since the Marine Corps requires many of its service men and women to share rooms while in garrison, it makes the issue trickier. The Department of Defense’s review of the controversial 1993 law is due to be completed December 1.