White House-watchers saw the heavy hand of the resident red-baiter, Pat Buchanan, on Ronald Reagan's address to the United Nations General Assembly. The president's trusty wordsmith from his winning presidential campaigns, Kenneth Khachigian, was recalled to duty to write a hard- edged first draft. It was a political document, calculated to get the United States off the arms control defensive and on to a "broader" agenda for the Geneva summit.

But to see it as a summit game plan is to suggest that it isn't also authentic Reagan policy. There's the pity. As a tactical stroke it made a certain sense. As policy for the real world, it makes almost no sense at all. And the more you examine the president's U.N. speech, the more apparent it is that this was vintage Reagan policy for his own real world.

What was heard in the General Assembly on Thursday was, in short, a Reagan Doctrine for foreign policy.

Now that's not the kindest thing to say when you consider the shelf life of presidential doctrines: Truman's, Eisenhower's, Nixon's, Carter's. But I'm only picking up on what other people have been saying -- people such as Jeane Kirkpatrick and the crowd at the Heritage Foundation.

Although it went largely unnoticed, Heritage had a symposium not long ago on "Reagan Doctrine." Rep. Jack Kemp called on Kirkpatrick to present what she called her "formulation of the operational code that I believe to be present in the president's views and policies of the last 41/2 years." Her statement was subsequently put out in a pamphlet titled "The Reagan Doctrine and U.S. Foreign Policy."

"The point of departure of Reagan Doctrine," Kirkpatrick said, "is the idea of freedom." At the "core" of his world view, Reaganid last week, there is "an eternal truth: Freedom works."

For her part, Kirkpatrick said, "The president's response to imperial growth of the U.S.S.R. has been to clearly affirm American solidarity with people struggling to prevent their incorporation into the Soviet empire or to regain their freedom." That's what Reagan was saying at the United Nations.

Kirkpatrick found her Reagan Doctrine in a passage from the president's State of the Union message back in January 1984: "We must not break faith with those who are risking their lives on every continent, from Afghanistan to Nicaragua, to defy Soviet-supported aggression and secure rights which have been ours from birth. Support for freedom fighters is self-defense."

Last week, the president said almost the same thing. If his proposals for a negotiated settlement of five anticommunist insurgencies (in Afghanistan, Cambodia, Ethiopia, Angola and Nicaragua) did not result in "definitive" progress, "America's support for struggling democratic resistance forces must not and shall not cease."

Kirkpatrick is not alone in her tub- thumping for a "Reagan Doctrine." Richard Nixon used the phrase in his recent article in Foreign Affairs magazine offering guidance in the administration's approach to Geneva. But Nixon and Kirkpatrick put their finger, by design or inadvertence, on the reason this doctrine makes so little sense.

Nixon conceded that we can't expect the Soviets to stop being "dedicated to expanding communist influence and domination in the world." Reagan also spoke (twice) of "deep and abiding differences" between the United States and the Soviet Union that put us "into natural conflict and competition with each other." But then he turned around and asked the Soviets to help promote negotiated settlements of the five conflicts in the world where the ideological lines are most sharply drawn. And he gave no sign that he would accept anything short of a "democratic reconciliation" of communist regimes in all those countries "with their people."

So negotiations "among the warring parties in each country" hardly look promising. But the Reagan Doctrine, according to Kirkpatrick, has strict limits: "It should be emphasized that the sympathy, solidarity and assistance offered by Reagan Doctrine do not include U.S. participation in combat."

If she's got it right, what the critics are already saying about U.S. "covert" assistance to the Afghan rebels becomes sadly appropriate: the level of American aid gives the rebels too little to win with -- "only enough to die." Yet, successful American support for anticommunist insurgency seems to have been the centerpiece of the Reagan administration's approach to East-West relations for at least two years.

So you have to believe Reagan meant it when he said last week that "the promise of the future lies not in measures of military defense or the control of weapons, but in the expansion of individual freedom and human rights." And if that's the agenda for the summit, you also have to wonder whether its epitaph will be any cheerier than John F. Kennedy's for the Vienna summit in 1961: "It's going to be a cold winter," he told Nikita Khrushchev.