Remember when they called him a nerd? When he was mocked as the gutless wonder? Does everyone recall those days in 1988 when critics said George Bush was indecisive? The caricature came back to mind last week when the real George Bush stood up.

His pledges of nuclear disarmament are stunning. They also are unconditional. These are not qualified proposals, hanging upon the contingency of complementary Soviet response. The president is acting unilaterally as commander in chief."I am therefore directing that the United States eliminate its entire worldwide inventory of theater nuclear weapons . . . The United States will withdraw all tactical nuclear weapons from its surface ships and attack submarines . . . I am directing that all U.S. strategic bombers immediately stand down from their alert posture . . . I am terminating the development of the mobile Peacekeeper ICBM . . ."

It is a fair assumption that before announcing these steps, Bush privately had obtained assurances from Mikhail Gorbachev and Boris Yeltsin that the Soviet leaders would respond in kind. The threat of nuclear holocaust has not ended - in some degree it will never end - but overnight that awful, awesome possibility has been greatly diminished.

In this cynical city, cynical motives at once are assigned to Bush's initiative. Since the pinnacles of Desert Storm, the president's approval rating has been steadily dropping. Several Democrats have announced plausible candidacies against him in 1992. To regain the spotlight, and to emphasize the inexperience of his prospective opponents, the speech was a political ploy.

It is further objected that the key proposals really are old stuff. Paul Nitze was trying to sell Ronald Reagan and Caspar Weinberger on naval nuclear disarmament six years ago. The mobile ICBM already was in trouble on Capitol Hill.

A simpler explanation is much closer to the mark. Bush felt the time had come to match the dramatic events in the Soviet Union with a dramatic response here at home. The Soviet people are in for a rough winter. If their morale can be lifted by lessening the tensions of nuclear arms, so much the better.

Bush's directives are indeed good news. These nuclear artillery shells, these nuclear missiles, these shipborne nuclear bombs are not merely to be withdrawn. For the most part they are to be dismantled and destroyed.

Many nuclear weapons will remain - the exact numbers and descriptions will not be made public - but these weapons will be "secured in central areas where they would be available if necessary."

Perhaps that point should be emphasized. Bush's unilateral decisions will not leave the United States naked to nuclear assault. Our nuclear arsenals are now thought to contain the rough equivalent of 4 billion tons of TNT. After Bush's terminations, it will be half as much.

Surely the remaining nuclear weapons are enough - more than enough! - for any foreseeable mission. It never has made sense for the United States and the Soviet Union to maintain nuclear arsenals of sufficient power to destroy the planet Earth. Once the president's initial steps have been completed, work should begin toward further reductions.

Some of the soundest advice ever given was offered to the fearless maid in Spenser's "The Faerie Queene": Be bold! Be bold! Be not too bold! Last week, Bush acted perfectly on that advice.