Some versions of the story say that Nimrodi and Schwimmer tried to cheat the Iranians. Others say that it was the Israeli Defense Ministry that attempted the switch. Still others say the Americans were responsible, but used the misstep to sideline Nimrodi and Schwimmer and to open a direct U.S. back-channel to Tehran.

FORMER CORRESPONDENT

Whatever the reason, the Iranians were angry, and in December 1985 Peres effectively replaced the two arms merchants with Amiram Nir, who until then had known little of the Iranian arms deal despite his job as Peres's counterterrorism adviser, a job that put him in charge of coordinating the activities of Israel's five intelligence services in the war against terrorism.

Nir, 36, ruggedly handsome, was an odd choice for the counterterrorism job. To the dismay of Israel's intelligence directors, he had spent only three years in the army, had no counterterrorism experience and had worked 10 years as a military correspondent for Israeli television.

But Nir was close to Peres, one of the young, bright aides who are known here as "Peres' Boys." When Peres was inaugurated in 1984, Nir was initially touted as chief administrative secretary to the prime minister, a job he scorned.

"That's a job in the rear guard, behind the lines. I like to be on the front lines, on the firing lines, " he was quoted as saying at the time. In fact, Nir was wounded three times covering Israel's wars. He lost an eye in a car crash, yet Israeli journalists still write that he lost it in battle.

Nir's replacement of Nimrodi and Schwimmer indeed put him on the front lines.

Nir became the Israeli contact with North, who wound up in day-to-day charge of the arms sales to Iran after McFarlane resigned and was replaced by Poindexter. Nir set up at least one meeting between himself and Ghorbanifar without informing either Schwimmer or Nimrodi.

'STRAIGHT TO PRESIDENT'

The chemistry between Nir and North must have been outstanding. Here were two young, aggressive, counter-terrorism officers, criticized by some factions at home yet secretly wheeling and dealing with the Khomeini regime with the approval of Reagan and Peres.

Nir and North talked frequently, and early this year, Nir met with Khashoggi and Ghorbanifar. According to an account published Friday in the Israeli newspaper Ha'aretz, Nir told them "From here I'm going straight to the President of the United States."

In May, Israel shipped at least 2,000 TOW missiles to Iran. In July, the Rev. Lawrence Jenco was released by his Lebanese captors.

Nir has declined public comment on the affair, but has reportedly told Israeli investigators that he was not aware that North was diverting profits from the Iran arms sales to the Nicaraguans, in possible violation of a U.S. congressional ban on American aid to the contras.

That is one of the key questions that American investigators will have to answer as they go about the task of unraveling the maze of U.S.-Israeli-Iranian contacts involved in what has come to be known as "Irangate."