POLITICS ’88 : Bush to Defend Downing of Jet at U.N. Session : His Presence Reflects Importance of Issues, President’s Aide Says

Vice President George Bush, accorded a platform that will emphasize his international experience, will deliver the American response at a U. N. Security Council debate today on the destruction by a U.S. warship of an Iranian jetliner carrying 290 people, the White House announced Wednesday.

With unusual fanfare, White House spokesman Marlin Fitzwater said that President Reagan had asked Bush to make the address, but Fitzwater denied the move was motivated to boost the vice president’s public profile.

The speech by the unofficial Republican presidential nominee will come just four days before the opening of the Democratic National Convention. And it accentuates topics--foreign policy and diplomacy--that Bush advisers see as vulnerabilities for virtual Democratic nominee Michael S. Dukakis.

‘Can’t Wait to Get Up There’

The vice president, reminding members of the American Farm Bureau in Washington on Wednesday that he served as U.N. ambassador in the Richard M. Nixon Administration, said he “can’t wait to get up there and defend the policies of the United States.”

As he has since U.S. officials announced that a missile from the Vincennes had mistakenly downed Iran Air Flight 655, Bush strongly defended the cruiser’s captain, Will C. Rogers III.

“Efforts to second-guess the captain of that ship will be rebuffed in what I am going to say,” Bush told the farm bureau members. “You see the second-guessing going on that suggests that the United States was wrong, this captain was wrong--his ship under fire, seven warnings and he was trying to protect the lives of these American kids. . . . “

Iran asked for the Security Council meeting in the wake of the July 3 incident, which occurred when the Vincennes fired two missiles at the jetliner in the mistaken belief that it was a threatening military aircraft. The Vincennes was involved in a skirmish with Iranian gunboats as the jetliner approached the cruiser in the southern Persian Gulf.

Agrees to Compensation

President Reagan sent a message of formal regret to Iran the day of the shooting, and on Monday the White House announced that Reagan has decided to offer cash payments to the families of the victims. That decision, U.S. officials said, does not imply an admission of wrongdoing.

White House officials portrayed the unusual assignment as a natural bequest to Bush, given his U.N. tenure from 1971-73 and his frequent representation of the United States in international circles.

“The vice president’s participation reflects the importance of the issues which are at stake,” said Fitzwater, Bush’s former spokesman. “The Iran Air tragedy . . . is a powerful reminder of the urgent need to end the brutal and senseless Iran-Iraq war.”

Fitzwater, asked specifically whether the decision to dispatch Bush to the United Nations was politically motivated, said of such suggestions: “They’re wrong.

“The issue is that we believe this is a matter of the highest importance to the United States and to the world,” he said.

The spokesman said Bush’s presence will underscore “the United States’ concern on this matter, the seriousness with which we take it.”

“And that is our motivation in the sense that the vice president can make these points forcefully and dramatically,” Fitzwater said, adding that Bush, as a former ambassador, “is quite familiar in the hallways of the U.N.”

Will Call for Cease-Fire

Bush did not specify the substance of his planned remarks, but Fitzwater and other officials indicated he would use the forum to argue for enforcement of a 1987 Security Council resolution calling for a cease-fire in the Iran-Iraq war, whose hostilities prompted the American presence in the gulf.

The vice president, who has been repeatedly briefed on the matter, is scheduled to make the American case after an opening statement by Iran. Bush is then expected to defer in any ongoing debate to U.N. Ambassador Vernon A. Walters. In making the announcement Wednesday, the White House allowed television cameras to record Fitzwater’s comments in the press room. Bush staff members earlier were told to keep the news quiet in deference to the White House.

In the Persian Gulf, a Navy team is in the midst of what was originally forecast as a two- to three-week investigation of the airliner incident. Fitzwater said Wednesday the probe “probably will go on somewhat longer than that.”