When Capt. Larry Dibble wanders into Greece Olympia High School, just outside Rochester, he is greeted with smiles and handshakes. Teachers invite him into their classrooms to talk to students about joining the Marine Corps. The school provides an almost-complete list of student names and telephone numbers.

In another suburb, at Fairport High School, Dibble is barred from setting up a recruiting table. Appointments are required to talk to students, and interviews are allowed only in the guidance office. The school will release student contact details only with written parental approval.

The different receptions reflect the twin poles of a nationwide debate about military recruiting in high schools that has heated up with the war in Iraq and the increasing demand for military manpower. As pressure mounts on recruiters to meet their monthly targets, principals across the country are grappling with difficult decisions over how much access to provide the military.

A little-noticed clause in the 2002 No Child Left Behind Act requires high schools to hand over students' names, addresses and telephone numbers to military recruiters as a condition of receiving federal aid. But some school districts are challenging the military's interpretation of the law, arguing that they are obliged to protect the privacy rights of their students.

"We're not going to give out information about our students unless we absolutely have to," said David Paddock, principal of Fairport High, who placed strict limits on the activities of military recruiters after a verbal confrontation between a Marine sergeant and a student peace activist. He describes the school's policy as "pro-kid, not anti-military."

Developments in Fairport, a largely white school district in an affluent suburb of Rochester, are being closely watched by other school districts unsure about their obligations under the Bush administration's signature education initiative. Some previously recalcitrant districts have begun to provide student information to the military after being threatened with retaliation by the Department of Defense, while others are reevaluating their access policies after reports of misconduct by military recruiters.

In one well-publicized case in Colorado, Army recruiters were tape-recorded encouraging a student journalist posing as a high school dropout to create a diploma from a non-existent school to comply with military enlistment requirements. They also were heard giving him advice on how to disguise a chronic "marijuana problem" and how to pass a mandatory drug test. The head of Army recruiting in Denver, Lt. Col. Jeffrey Brodeur, described the practices as "completely unacceptable."

The Army Recruiting Command declined to permit a reporter to observe its operations in Rochester, referring questions to the Pentagon. But the Marine Corps, which has been more successful in meeting its monthly recruiting targets, allowed a reporter to spend a day with its recruiters as they sought enlistees in Rochester area high schools.

The day begins at 8 a.m. in the Marine Corps recruiting office in downtown Rochester, one of several dozen recruiting stations in New York state. The drive is planned like any other military operation, with color-coded pins on maps denoting "target schools," clearly defined objectives and a strategy for achieving them. The Rochester region is expected to "ship" -- military jargon for "deliver" -- 101 new recruits to boot camp every year, part of a nationwide total of about 40,000.

It is a labor-intensive, frequently frustrating business. An average of 10 telephone calls is required to produce a single "contact" with a prospective recruit. Five or six contacts are needed to gain an "appointment." It takes two or three appointments to set up an "interview," a three-hour session that tests the persuasive powers of the recruiter. One in five interviews results in a "contract," or a commitment to join the Marine Corps.

"You can't expect immediate results," says Dibble, who oversees high school recruiting efforts in western New York state. "It's very hard work."

After morning strategizing, the Marines head to Greece, a bedroom community on the outskirts of Rochester. This is prime recruiting territory: middle-class, conservative, economically depressed. Several large companies in the Rochester area, including Kodak and Xerox, have cut back in recent years. Other than the military, there are few jobs for high school graduates.

A former Olympia student, Lance Cpl. Brian Schramm, was killed in Iraq last year while serving with the Marines, but his death does not appear to have hurt recruiting at the school. Sgt. Charles Ray exudes confidence as he delivers his sales pitch to an automotive repair class. He starts with the "tangibles" -- excellent health care, subsidized college tuition, a secure job -- before moving on to the "intangibles" cherished by the Marine Corps: pride, a sense of belonging, leadership skills.

"Just think about it," he tells the class. "Former Marines account for less than 1 percent of the U.S. population. But 30 percent of the heads of America's top companies are run by ex-Marines." Dibble is pleased with the sergeant's performance, though he notes that the "stats were a bit off."

At Fairport High School, the Marines head to the student guidance office to "establish rapport." With more than 1,600 students, the school remains a top priority for Marine recruiters, despite the lack of access to students. Over the past five years, 28 Fairport graduates have joined the Marines. This school year, only one student has signed a contract.

According to William Cala, superintendent of the Fairport school district, the "aggressiveness" of Marines and other military recruiters has "increased dramatically" because of the war in Iraq. "The recruiting goals have been set very high. The recruiters have to meet them, or they will be held accountable."

Cala cited an incident last November in which a Fairport High student peace activist and a Marine recruiting sergeant got into a verbal altercation in a hallway. Although there are differing accounts of what took place, the sergeant later left a message on the student's home answering machine threatening to report him to the police for "destroying government property." The student went to the principal in tears, and the principal asked the military to leave the building.

"If there's a confrontation in my school between a student and recruiters, and the kid ends up crying, I am going to side with the kid," said Paddock, the principal.

Fairport High School is in the only school district identified by recruiters as being in "non-compliance" with the information-sharing requirement of No Child Left Behind, Pentagon spokeswoman Lt. Col. Ellen Krenke said. The Defense Department is working with the district to fashion a solution, she said.

The law permits families to withhold student contact information from military and college recruiters, and stipulates that schools "notify" parents of that option.

How the opt-out form is worded can make a crucial difference. Last year, only 80 families gave Fairport High School permission to turn over student contact information to the military. The remaining 1,500 families asked for contact information to be withheld or failed to return the form, which was interpreted by the school district as non-consent. In nearby schools, including Olympia, only a few dozen parents objected to the release of information. The majority failed to return the forms, which was considered consent.

Other school districts are coming under pressure from networks of anti-war activists and parents concerned with privacy issues to limit their cooperation with military recruiters. The Rochester City School District is one of dozens across the country reviewing its policies after complaints from parents and students about the lack of adequate information about the opt-out choice. The parent-teacher-student association at Garfield High School in Seattle voted 25 to 5 last month to adopt a largely symbolic resolution that "public schools are not a place for military recruiters."

Over the past few weeks, Washington area schools have reported increased interest from parents in withholding student information from recruiters. Montgomery County school spokesman Brian Edwards said that the school system was considering revising the permissions process to provide families with a better understanding of what happens to student contact information.

Currently, Edwards said, information published in school directories is automatically available to military recruiters under No Child Left Behind.

A Fairfax County school system spokeswoman, Kitty Porterfield, said that schools there provide "several written communications" to parents outlining opt-out procedures.

The controversy over military recruiting in high schools has spawned half a dozen Web sites calling on families to sign forms asking that student information be withheld from recruiters. The founder of one such site, rock musician Justin Sane, said that more than 7,000 people had signed a petition on militaryfreezone.org to request the withholding of contact information.

Dibble said that manpower demands caused by the Iraq war are forcing recruiters to work "harder and smarter."

The opt-out movement comes as the military is struggling to meet its recruitment targets. The Army Recruiting Command reported at the end of April that it was 16 percent below its year-to-date recruiting target for the active Army and 21 percent below target for the reserves. The Marines slightly exceeded "shipping" targets during the same period but were down 2 percent in signed contracts, which represent a commitment to join the Marines at a future date.

Critics of the recruitment provision of No Child Left Behind argue that an opt-in policy on sharing contact information might be more beneficial. "We are providing the military with a list of those students most interested in joining the military," superintendent Cala said. "That's very valuable. It eliminates the need for huge numbers of cold calls."

Marine recruiters disagree. They say that they need comprehensive lists because many students become interested in the military only after being contacted by recruiters. If they do not get the lists from the school districts, they must build them from other sources, including yearbooks and other students.

"Getting a list from a high school makes our life a little easier," Dibble said. "But whether or not they give us a list, we will get the information one way or another. We want to provide all students with the Marine Corps option."

Students at Olympia High School leave their contact information for Gunnery Sgt. Jason Romano. Districts are supposed to provide directories to recruiters as a condition of the No Child Left Behind Act, passed in 2002.Getting young men such as Cameron McClarey into the recruitment office increases odds that they will enlist.Marine Staff Sgt. John Delgado tries to connect with potential recruits. About 10 calls are needed to yield a contact, which is step one toward enlistment.