It's 3 a.m. You receive a call in your hotel room telling you that Iraqi terrorists have hijacked a plane carrying plutonium from France to Japan, and that your presence at the United Nations is urgently needed.

Welcome to the 34th annual Harvard National Model United Nations.

The University-hosted U.N. simulation held last week brought together nearly 1700 college students from more than 140 schools nationwide to discuss politics and policy at the Copley Place Marriott, conference organizers said yesterday.

John P. Stanley '90, committee director on economic and financial issues, said Model U.N. leaders wanted to "immediately challenge the delegates," with crises, such as the Iraqi terrorist situation.

Other simulations presented to the delegates included the formation of a white secessionist state in South Africa and a call for the return of former dictator Idi Amin to Uganda, according to Marc S. Sabatine '90, the specialized agencies undersecretary general.

"We really tried to take a unique approach to the issues we dealt with," said Sabatine. "We wanted to have all of the topics really apply to the real world."

According to Linda A. DiMeglio '90, director of delegate services, the conference is comprised of 18 committees divided into three categories: the general assembly, the economic and social council and the specialized agencies--which include the Security Council, the Court of Justice and the International Atomic Agency.

The summer before the conference, DiMeglio said, each participating school is assigned a nation to represent, and given a "study guide" on topics to be discussed at the conference. Model U.N. organizers said that attending delegates accounted for approximately 140 of the 159 member countries in the United Nations.

After debate, committee resolutions are developed and put before the mock General Assembly for approval in a procedure identical to that used by the United Nations. Students said the practice of developing resolutions during the conference is unique to Harvard, because other model U.N. programs often hold conferences with pre-set agendas.

In past years, Harvard's Model U.N. was complicated by security problems, said Andrea G. Cohen '90, general assembly undersecretary. But, Cohen added, this year was virtually problem-free because, due to hotel renovations at the Marriott, students stayed at six different local hotels, with only about one-third of the participating students housed at the Marriott.