Washington ? The Supreme Court ruled unanimously Monday that the government can force colleges to open their campuses to military recruiters despite university objections to the Pentagon’s “don’t ask, don’t tell” policy on gays.

Justices rejected a free-speech challenge from law schools and professors who claimed they should not have to associate with military recruiters or promote their campus appearances.

The decision was a setback for universities that had become the latest battleground over the military policy allowing gay men and women to serve only if they keep their sexual orientation to themselves.

The ruling does not, however, answer broader questions about the policy itself. Challenges are pending in courts in Boston and Los Angeles that could eventually reach the high court.

Justices seemed swayed by the Bush administration’s arguments that after the terrorist attacks, and during the war in Iraq, the government had a responsibility to bolster its recruitment.

Chief Justice John Roberts said that campus visits are an effective recruiting tool. And, he said, “a military recruiter’s mere presence on campus does not violate a law school’s right to associate, regardless of how repugnant the law school considers the recruiter’s message.”

The 8-0 decision upheld a federal law that says universities must give the military the same access as other recruiters or forfeit federal money.

Justices ruled even more broadly, saying that Congress could directly demand military access on campus without linking the requirement to federal money.

“When you’re in the middle of war, even if it’s not a terribly popular one, courts are hesitant to tie the hands of the military,” said Jon Davidson, legal director of gay rights group Lambda Legal.

Jay Sekulow, chief counsel for the American Center for Law and Justice, called the decision “an important victory for the military and ultimately for our national security.”

The military’s policy had put college leaders in a thorny situation because of campus rules that forbid participation of recruiters representing agencies or private companies that have discriminatory policies.

Most college leaders have said they could not afford to lose federal help, some $35 billion a year.

Roberts, writing his third decision since joining the court last fall, said there are other less drastic options for protesting the policy. “Students and faculty are free to associate to voice their disapproval of the military’s message,” he wrote.

The court roundly rejected arguments that the policy raised important First Amendment free-speech issues for school leaders.

“Compelling a law school that sends scheduling e-mails for other recruiters to send one for a military recruiter is simply not the same as forcing a student to pledge allegiance, or forcing a Jehovah’s Witness to display the motto ‘Live Free or Die,”‘ Roberts wrote.

Roberts filed the only opinion, which was joined by every justice but Samuel Alito. Alito did not participate because he was not on the bench when the case was argued three months ago.