Whatever the ultimate cost of the un-noticed burial of the President's Foreign Intelligene Advisory Board, th short-run effect is to silence the most important intelligence sounding board - other than U.S. intelligence agencies themselves - for every President since Dwight Eisenhower.

The most persuasive agent on President Carter last month in recommending the death of the board was Adm. Stansfield Turner, the new Director of Central Intelligence. But Central Intelligence directors have never particularly liked the advisory board with its high-powered membership drawn from former government officials and the loftiest niches of American science and business. To them, it represented a threat as a competitor for the President's ear and a source of intelligence aspiration.

PFIAB, for one notable example, engineered the intelligence breakthrough by the CIA that led to spy-in-the-sky reconnaissance. That might have been delayed for years without hard pressure from PFIAB and Edwin H. Land, Polaroid chairman and a PFIAB member since 1961.

The risks inherent in killing PFIAB are manifold. It was PFIAB that persuaded former President Ford and ex-CIA Direcotr George Bush to engage an outside team of hard-line experts to debate CIA's estimate of Soviet intentions and capabilities last summer.

Those experts, called "Team B," produced much harsher estimates than the CIA's "Team A" of experts. The result: a much harder-nosed "national estimate" regarded by experts as far more realistic than estimates by the CIA acting alone.

The point man in exposing the CIA's experts to such formidable competition was Leo Cherne, the board's last chairman (a post previously held by Dr. James Killian, Clark M. Clifford and Gen. Maxwell Taylor since Eisenhower established PFIAB in 1956).

The scuttling of PFIAB is clearly tied to the fear of similar outside competition for the intelligence bureaucracy, plus a desire to centralize control over all intelligence within the CIA and the National Security Council staff inside the White House.

The explanation for this, a view widely held by skeptical outside experts on Soviet weapons and geopolitical planning, is the bureaucracy's zeal to screen out points of view that challange the prevailing administration line. Consider the following incidents:

Dr. Richard Pipes, the Harvard Russian scholar who played a key role in "Team B" last summer, believed he had an informal agreement from the Arms Control and Disarmament Agency for up to $7,500 to help finance a Harvard-MIT conference on basic Soviet strategic doctrine. But ACDA, now under controversial director Paul Warnke, informed Pipes last month it could not help fund the project (even though Warnke has publicly said he has no idea whether Moscow seeks military superiority over the U.S. or simply equality).

An invitation to retired Gen. George Keegan, foermer Air Force Intelligence chief, early this year to lecture at the Air University at Maxwell Air Force Base was withdrawn. The only explanation: The Pentagon and/or White House did not want Keegan to be sponsored by the government in view of his well-known alarm over Soviet intentions.

Concern within the Defense Intelligence Agency that the Carter administration - and Turner - may be plotting enhancement of CIA at the expense of DIA.

What makes the demise of PFIAB more mystifying is that two authors of the Senate Intelligence Committee's final report on "the President's office" last year, David Aaron and Rick Inderfurth, said the board had been "useful," partly because "its advice and recommendations have been for the President. As such, the executive nature of this relationship should be maintained."

Aaron is now deputy to national security adviser Zbigniew Brzezinski; Inderfurth is Brzezinski's special assistant. They headed Jimmy Carter's transition team on intelligence, proposing to abolish PFIAB despite what they wrote in that reported only months earlier.

One conclusion from this is that the incoming administration was planning to centralize long before it took office, a possibility duly reflected by Aaron and Inderfurth. Their report sat on the President's desk until early May when, pressed by Turner, Carter delivered the coup de grace to PFIAB - a blow to challenges from outside the bureaucracy that have proved invaluable to U.S. intelligence in the past.