When Oakton High School students submitted their choices for a country to represent at a mock session of the United Nations, Iran was fifth on their list. That was in October.By the time the assignments were made, and Oakton of Vienna, Va., was tagged to assume the role of Iran, militant terrorists had seized 50 American hostages and Iran was dominating the news.

"And I thought what could be better, we're right on the hot seat," said Jeff Van Dreal, 17, the wiry and exuberant chief delegate of the Oakton students. As he walked through the halls of the Shoreham Hotel yesterday, where the annual North American Invitational Model United Nations was meeting, no outward hostility was evident.

But Van Dreal and his eight Oakton schoolmates have received some verbal assaults as 1,200 students from more than 100 schools spent the first of four days of meetings, assuming other countries' politics, perks and personalities.

The Oakton students have found that their representation has put them in the middle of a tug-of-war between the resurgent patriotism evident among their peers and the demands placed on them by the assumption of the Iranian point of view for the mock debate.

"I really hesitated at doing this. All I could think was, here I am, a traitor, a Benedict Arnold," said Heidi Godman, a 16-year-old sophomore. "Now that I am here, people wouldn't listen to me. I really feel strange."

One of her colleagues, Baughan Legg, 17, and the student coordinator for the presidential campaign of Sen. Edward M. Kennedy (D-Mass.) in Fairfax County, was primed for a fight. "I love controversy. I thought it would be explosive," he said.

Since the sessions began on Thursday evening, the Oakton students who are identified on mustard yellow name-tags as delegates of the Islamic Republic of Iran, have been peppered with questions on their motivation by the hotel staff and other students.

"In the legal committee, we were discussing the rights of journalists in the combat zone. And I said Iran believed that journalists were neutral, but once they became a problem, they had to go," said Djohn Dongan, 17, "and I was shouted down as a hyprocrite."

In another session, Mary Harroun, 18, passed the Cuban delegation a note, asking them to put out their cigars. The reply came back, "F--- Iran."

The Oakton students are only one dramatic curiosity at the mock United Nations. The students representing the Soviets were trying to outshout everybody. And a man dressed in the white scarf and olive fatigues of the Palestinian Liberation Army patrolled the halls, seemingly looking for attention.

Now in its 17th year, the mock sessions are a major project of the Georgetown University International Relations Association. The enterprise brings about $80,000 into the hotel, according to a Georgetown spokesman, with the schools and students paying their own delegate and delegation fees, rooms and transportation.

In preparation for his role, Van Dreal went to the Iranian Embassy and was briefed for a hour and a half on foreign policy.

And the press.

After an interview yesterday, Van Dreal announced that none of his delegates could have their pictures taken as Iranians. "The only was for us to be interviewed as Iranians is on live television. The American propaganda machine will distort what we are saying. If you come in while we are debating, we will sit down," said Van Dreal. But they agreed to be photographed as Americans in the hall.

After nearly four months of intense study and discussion, the Oakton students haven't reached a consensus on how they feel about Iran.

"I know now that the students holding the hostages don't represent all points of view in the country," said Harroun. "And that's confusing as I deal with my patriotic feelings. I am still upset that they took the Americans hostage. But I have a better understanding of their bitterness toward the shah. It's very frustrating."

Since November, according to the students, Oakton has been dominated by discussions of Iran, Afghanistan, the draft and U.S. participation in the summer Olympics. Graffiti ("Nuke Iran") appeared on the bathroom walls; American flags replaced smile buttons on hats.

In the midst of a school talent show recently, a student changed from a folk song to a patriotic number putting on a helmet and beating on it.

"I wouldn't call that patriotism," said Peter Cook, 17. What we have found is that people feel freer about expressing their patriotism."