Washington faces conflicts - one with friend, one with foe. But Japan trade friction and arms cuts with Soviets can be worked out

This is a good week for reflecting on what the world would be like were there no nuclear weapons forcing everyone to be careful about what each superpower does and says. Right now the United States and the Soviet Union are taking little anxious, nervous half-steps toward possibly reducing the number of nuclear weapons that each can throw at each other in the European part of the world.

And this week, the prime minister of Japan was in Washington trying to work out with the President of the United States a sensible compromise over the terms of trade between the two countries.

In both cases, agreement is extremely difficult, but will almost certainly be achieved.

The difficulty of reaching an arms control agreement between the US and the Soviet Union was illuminated by the fact that the White House this week publicly rebuked one of its own inside arms control advisers, Gen. Edward Rowny, for having strayed from the President's pro-arms-control posture of the moment.

The difficulty of working out new, different, and better fair-trade rules between Japan and the US is underlined by the hard fact that Japan's current prosperity is heavily based on earnings that the US says gives Japan a net profit of some $60 billion a year. This amounts to roughly half of the current US deficit in its foreign trade account. This condition, if unchecked and uncorrected, could virtually bankrupt the US in a matter of the next two or three years.

In the pre-atomic age, the US and the Soviet Union would probably be at war with each other over their many differences and their many mutual points of friction. In the nuclear age, they find themselves forced into attempting to reduce the number of weapons they aim at each other.

Many a war in the pre-nuclear age was waged over problems of trade less serious than those that brought Yasuhiro Nakasone of Japan to Washington.

It is essential to both the US and Japan that they work out new rules governing their trade relations. They have become each other's most important suppliers and customers. They are the two largest and most productive economies in the world today. They are massively dependent on each other. They must come to mutually acceptable terms of trade, for the alternative could be too damaging to the economies of both.

Add that the US position in the world is strong because it is politically and militarily associated with Western Europe on one side of the Soviet Union and with Japan and China on the other side of the Soviet Union. The triple relationship is America's strength against the Soviet Union. Japan is a vital feature in this system of alliances and friendships. The US dare not let itself get into a trade war with Japan.

At the same time, neither the US nor the Soviet Union dare let itself get into such a degree of uncontrolled hostility with the other that the use of nuclear weapons might occur. The time has passed when either thinks seriously of ``trying to win a nuclear war.'' Both know that there is no victory in such a war.

But over the past week, General Rowny, who was hired in 1981 as a major adviser on nuclear weapons to the Reagan White House and has been in and around there ever since, spoke up in public in support of criticism of the President's current arms control position that had come over the weekend from former Republican President Nixon and Henry Kissinger, his secretary of state.

The Nixon-Kissinger criticism had been printed in the Washington Post and Los Angeles Times last Sunday. It asserted that the prospective deal to eliminate intermediate-range nuclear weapons from the European theater should be rejected unless accompanied by a reduction in Soviet conventional weapons in Europe and unless it also included the total elimination of all intermediate-range missiles worldwide.

General Rowny was quoted the next day as endorsing the Nixon-Kissinger position. On Tuesday, the White House spokesman said the Rowny remark would complicate talks with the Soviet Union.

In other words, there is a difference of opinion inside the Republican Party and even inside the White House itself over what kind of a deal on nuclear weapons in Europe is desirable and in the US interest. President Reagan is going to have to try to win over at least Mr. Nixon to his prospective agreement with the Soviets. It would be politically imprudent for him to make a deal that was being repudiated by such an important voice in his own party.

But the key point remains. Even as vehement a critic of the Soviets as Mr. Reagan is in the process of doing diplomatic business with them for the double purpose of trying to reduce the number of weapons that arm their rivalry and of seeking new rules and standards of conduct that can hope to keep their rivalry within peaceable bounds.

The essential fact is that the two greatest military powers on earth are working toward peaceful coexistence instead of preparing for an inevitable war.

Six years ago when Mr. Reagan took office, a good many of the people in the Reagan political entourage talked differently. Some assumed, and said publicly, that the US was in ``a prewar situation.''

Those who thought and talked that way have for the most part departed. No prominent figure in the Reagan administration has talked about a nuclear war with the Soviets for some time now. These individuals came to Washington, they learned about the facts of nuclear war, and they have accepted, albeit if sometimes reluctantly, the conclusion that the first objective of government in Washington must be the avoidance of nuclear war.

So Mr. Reagan has come a long way from 1983, when the Soviet Union was the ``evil empire'' and the ``focus of evil in the modern world.''

As for Japan, the urge in both countries is probably toward at least a trade war. But Mr. Nakasone reached Washington to talk with people who know just as well as he does himself that agreement is an economic necessity for both.