In a changing world, inexperience is an asset for new secretary of state. As trade becomes the key issue, Baker takes on job unencumbered by old, cold war battles

This is Mr. Harsch's final column in this Pattern of Diplomacy series, which began in 1965. He will be spending most of his time in coming months writing books. It is a good thing, not a bad thing, that America's next Secretary of State, James Baker III, has had almost no experience in foreign policy and knows little about it. It is a good thing because he will be taking over the management of American foreign affairs in a new and different world.

The old year now behind us was a true watershed year. Change was enormous. The most spectacular change was that the Soviet Union went from being an expansionist imperial power to being a recessive imperial power. Equally important, though less visible, was that Western Europe is melding together into a coordinated economic force and is already developing an independent foreign policy.

The old world was a two-power world. The new world is a multi-power world in which Western Europe, China, Japan, perhaps someday India as well, will be as important as the Soviet Union.

Experience in the power politics of the old world would be a handicap, not an asset, to the man who will manage United States foreign policy during the years immediately ahead.

In picking Mr. Baker for the job, George Bush was doing exactly what Mikhail Gorbachev did when he sacked Andrei Gromyko, whose experience and training had been entirely in the cold war era, and brought in to replace him a man from the world of Soviet domestic affairs. Eduard Shevardnadze was as much a stranger to foreign affairs when he came to the Kremlin as Baker will be when he takes over the State Department.

It would be easier to understand the problem of adjusting foreign policy from yesterday's world to tomorrow's world if the cold war had been an actual hot war. Reflect for a moment on what happened at the end of World War II. Germany and Japan had been the enemies; the Soviet Union was a partner and ally. Yet within five years after that greatest of all world wars, the relationship of the US to friends and foes had been reversed. Germany and Japan had become friends and allies. The Soviet Union was the antagonist.

The men of the Kremlin go around these days joking that they have ``done a terrible thing to the Americans, we have deprived them of an enemy.'' It is an amusing joke until you think about it for a moment. It is true. Certainly they have done just that. They have given up the use of military power as the main instrument of Soviet foreign policy. They have turned instead to diplomacy, at which Russians have always been skillful. And their goal is no longer capturing lands and peoples. It is gaining access to modern technology.

The Soviets are doing this because modern Soviet leaders understand that economic health is the foundation of all power, either military or diplomatic. Without a modern economy no country in the world ahead is going to have influence beyond its borders.

The old year ended with the Soviet Union making overtures to Japan. There is still no peace treaty between the two. Technically, they are still at war, although not fighting. Japan has always insisted that it will not sign a peace treaty with the Soviet Union unless or until the Soviets withdraw from the cluster of small islands just north of Hokkaido, which the Soviets pinched at the end of World War II.

In the era of Henry Kissinger, the focus of all foreign policy was on the US-Soviet rivalry. It colored every relationship between any pair of countries in the world. Nothing else really mattered except these two mighty rivals. But not so anymore. It matters greatly, to all, whether Moscow finally makes peace with Japan.

As for Baker on the day he takes over the State Department, his biggest concern will be the terms of trade between the US and the emerging European Economic Community. And his second-biggest concern will be the terms of trade between the US and Japan.

If and when he gets those relations sorted out as best possible, he will find himself deep in consultation with all the important countries in the world about how to save the planet Earth from the galloping destruction of the natural environment. Can the rain forests of Brazil, Africa, and Southeast Asia be saved before it is too late?

Quality of life in the US and Soviet Union will be endangered more by the destruction of rain forests than by anything either is likely to do to the other. Both will probably spend more time talking to each other about such matters than about their rivalry.

It is a new world opening up in 1989, and it's a good thing that Baker approaches it with a mind uncluttered by memories of the battles of the cold war.