Having already promised high adventure and cash bonuses to lure young people into uniform, the Pentagon now wants Hollywood stars to glamorize its recruitment advertising. But some big names are reluctant to accept the casting call.

Defense Secretary William S. Cohen announced yesterday that he had personally solicited about a dozen movie celebrities and professional athletes to appear in a media campaign aimed at boosting enlistment in all branches of the military. "In principle they have agreed to help," Cohen told a gathering of reporters in his office.

Cohen specifically mentioned Julia Roberts, Tom Cruise, Harrison Ford and Steven Spielberg as possible participants in the efforts. Through various spokesmen, each of them confirmed yesterday that Cohen had contacted them, but denied that they had any plans to make recruitment commercials.

"We don't have firm commitments from these people and we may not get them, but we'll keep asking and we assume some others will sign up," responded Defense Department spokesman Kenneth H. Bacon.

Historically, movie stars and starlets have figured prominently in morale-building performances for troops overseas. But Cohen's plan would take the relationship with Hollywood in a new direction.

Cohen said he hoped to have recruitment commercials featuring Hollywood stars on the air by the end of the year--the first time since the creation of the all-volunteer force nearly three decades ago that the Pentagon has attempted to use celebrity sizzle to get young people to enlist.

Asked whether the Hollywood types would be held up as role models for potential recruits, Cohen said, "No, we are just looking at people with that status in society who might be willing to say positive things about the military."

Some branches of the armed forces have had trouble meeting their recruitment goals in recent years as the civilian job market has boomed and college scholarships have beckoned. The Army, for example, fell 8.5 percent short of its objective in fiscal year 1999. Cohen said yesterday that devising better strategies for recruitment has become one of his top priorities.

The idea of using Hollywood stars began to percolate after Cohen saw Spielberg's "Saving Private Ryan," an elegiac 1998 film about the Normandy invasion, Bacon said. That movie and other signs of rising popular appreciation for the World War II generation convinced Cohen that the entertainment industry might collaborate in promoting the military, Bacon said.

While the Vietnam War fomented a distant, sometimes hostile relationship between Hollywood and the armed forces, the tone has changed markedly in the last few years. Harrowing and heroic portrayals of the Army in such recent films as "Saving Private Ryan" and "The Thin Red Line" have replaced the unflattering portraits that prevailed in "Platoon," "Full Metal Jacket" and "Born On the Fourth of July." Even last year's "Three Kings," the edgy, off-balance look at the Gulf War starring George Clooney, portrayed American soldiers as moral and essentially good-hearted, even as they were stealing Iraqi dictator Saddam Hussein's gold.

"Patriotism is no longer unpopular," said Howard Suber, founding chairman of the producer program at UCLA's film school. "The Defense Department is no longer a politicized institution. It's no longer politically incorrect to even contemplate doing this [recruitment ads]."

Humanitarian interventions, Suber added, have helped to refashion the armed forces' image. "Right now, the military are the guys saving all those poor people in Kosovo," he said.

Cohen's decision, however, is hardly spontaneous. An outside review of Defense Department advertising last year also recommended a campaign that would use celebrities to persuade young people and their "influencers," such as parents and coaches, to consider a military life.

"In today's crowded media market that bombards kids with images, you have to find a way to turn heads, and these people who attract millions into theaters might get young people to check out the Army or the Air Force," said Bacon, the Pentagon spokesman.

Before the stars can recruit the troops, however, someone will have to recruit the stars. While President Clinton has close contacts in Hollywood, Bacon said the commander-in-chief has not been involved.

A spokeswoman for Roberts said yesterday that the actress met Cohen at the People's Choice Awards a few weeks ago, "but she has no plans to be in a recruitment commercial." Through a spokeswoman, Ford said he told the secretary of defense at the same awards show that "he'd be more than happy to do tapes or messages for the troops" but "would not, however, be available to do recruiting public service announcements."

Spielberg and Cruise similarly demurred when asked if they would go along with Cohen's plan. Spielberg's Los Angeles office said he is producing two television projects of his own involving the military, but he has no plans to direct recruitment ads.

Tom Cruise's publicist, Pat Kingsley, said Cohen had placed a call to the star yesterday afternoon. Cruise was unable to take it because he was skiing.