U.S. intelligence officials have "consistently underestimated" the Soivet military threat over the last 25 years and have let themselves be "politicized," Maj. Gen. George J. Keegan said yesterday.

Keegan, who retired in January as head of Air Force intelligence, called for a full-scale review of past intelligence estimates by an independent body to determine who has been right and who has been wrong about the Soviet threat.

Speaking at a luncheon sponsored by the American Security Council, a private group supporting a stronger military, Keegan said: "If there is a Watergate in this country, and there is, it has been in the monumentally incompetent judgmental process in this government regarding the nature, character and growth of the Soviet threat as it has evolved from year to year."

Keegan said that on the basis of his own examination of secret data on Soviet military activities, the Soviets are on the verge of technology to neturalize American missiles; have built military forces which could overrun Western Europe within 24 to 36 hours and have provided shelters against nuclear attacks for their weapons, their leaers and many of their citizens.

Keegan charged unidentified officials in the Kennedy administration with trying to suppress material about the Soviet threat that was more alarming than information they were releasing to the public. He included in this category books by Soviet Marshal Vkasilliy Sokolovsky and afoy Kohler, former American ambassador to Moscow.

The former Air Force intelligence chief also said it was high time to release to the American public the full papers the United States obtained from Soviet Col. Olev Penkovsky, who passed Soviet secrets to the United States. He argued that then the American people could make their own assessments of what the Soviets are up to militarily.

Turning to the threat that he sees from the Soviet buildup, Keegan said that Soviet leaders have put so much of their weaponry and command centers deeps underground that U.S. missiles no longer could destroy them in a retaliatory strike.

"What they've done over the last 20 years ahead of their American counterparts in developing a gun that would shoot electrons to destroy incoming missiles or warheads in a war. Keegan predicted the Soviet will have this new device "well before 1980."

As for the Soviet threat to NATO, Keegan said that "as early as 1977 or 1978 a Soviet war planner could have confidence that he could take Europe by force of arms with limited fighting in 24 to 36 hours with or without the use of nuclear weapons."

In another grave assessment of Soviets "could sink 75 per cent of the free world's surface fleet in a number of hours."

The former intelligence chief stressed that all this was not about to happen, saying, "We are not on the edge of the abyss," but that the Soviet threat is indeed real and alarming that "a global conflict is in gestation."