WASHINGTON The Pentagon unveiled a study on Tuesday that predicted little impact if the U.S. military ended its ban on gays, bolstering President Barack Obama's push to get Congress to repeal "Don't Ask, Don't Tell" by year-end.
Gay rights activists swiftly applauded the study, which dismissed or minimized concerns among some U.S. lawmakers and up to a third of the military about ending the policy.
Obama called for swift action by Congress, where he faces stiff opposition from Senate Republicans who are threatening to block him..
"I call on the Senate to act as soon as possible so I can sign this repeal into law this year and ensure that Americans who are willing to risk their lives for their country are treated fairly and equally," Obama said in a statement.
Still, top U.S. generals voiced concern about the fallout on U.S. forces fighting in Iraq and Afghanistan, and Defense Secretary Robert Gates warned they would need plenty of time to prepare for integration of openly serving gays and lesbians.
"An abundance of care and preparation is required if we are to avoid a disruptive -- and potentially dangerous -- impact on the performance of those serving at the 'tip of the spear' in America's wars," Gates told reporters.
At least 13,000 men and women have been expelled from the military since "Don't Ask, Don't Tell," which allows gays to serve in the armed forces as long as they keep their sexual orientation private, came into force in 1993.
The study dismissed as exaggerated notions that ending the ban would lead to overt promiscuity, widespread "effeminacy" among men and "unwelcome advances." It also opposed separate living quarters or bathrooms for gay or lesbian troops, a possibility raised in the past by some in the U.S. military.
It recommended a training program to educate soldiers on the implications of lifting the ban. Gates refused to say how long such training might take but warned that an immediate end to the ban through court action would be "dangerous."
"If a court ordered us to do this tomorrow, I believe the risk to the force would be high -- if we had no time to prepare," Gates said.
Still, the nine-month study concluded: "Our military can do this, even during this time of war."
The debate over ending the ban has evoked memories of past civil rights hurdles, particularly within the U.S. military.
The study noted the military had faced far stronger resistance to racial integration in the 1940s and 1950s, when the armed forces were emerging from World War Two and in the midst of Cold War tensions and the Korean War.
"But by 1953, 95 percent of all African-American soldiers were serving in racially integrated units, while public buses in Montgomery, Alabama, and other cities were still racially segregated," the study said.
The survey of just over 115,000 troops showed a solid majority did not believe repeal would affect their ability to do their jobs. Some 69 percent believed they had already worked with a homosexual.
The study acknowledged that a "significant minority" of about 30 percent overall expressed negative views or concerns about repeal. The figure was higher in the Marine Corps.
The "most intense and sharpest divergence of views" on repealing "Don't Ask, Don't Tell" came from the military's 3,000 chaplains, a large number of whom believe that "homosexuality is a sin and an abomination," it said.
Ending the ban has not been a top legislative priority for Obama in his first two years in office, but the repeal gained added urgency after fellow Democrats lost control of the House of Representatives and saw their majority slimmed down in the Senate in the November 2 congressional elections.
The White House sees a narrow window of opportunity to get the ban repealed in the three weeks before the current Democratic-controlled Congress adjourns for the holidays.
Some Republicans dismissed the survey results. Republican Senator Lindsey Graham said the survey was tainted this year when the House voted to repeal "Don't Ask, Don't Tell."
"Whether or not this policy needs to be changed, time will tell. I would like to hear an unbiased, unfiltered view from those who are serving, and then we will make an intelligent decision," Graham said.
Some Washington pundits have suggested that if Obama fails to do this, disillusioned gay voters could punish him in the 2012 presidential elections by staying away from the polls.
(Additional reporting by Tabassum Zakaria, Thomas Ferraro and Steve Holland in Washington and Steve Gorman in Los Angeles; editing by Mohammad Zargham and Cynthia Osterman)