JAPAN and America will shape the initial decades of the 21st century more decisively than any other two countries. Between them, they produce 40 percent of the gross world product and perhaps 85 percent of the world's leading-edge technology. They constitute the world's largest source of finance capital. They are the world's two economic and technological superpowers, as well as the primary agents of change. What happens between the United States and Japan may well be, in the long run, of greater consequence than what is happening in the Soviet Union, as important as that is. Yet the quality of the US-Japan relationship has plummeted. Expressions of scorn are commonplace on both sides of the Pacific. While forward steps are being taken in the affairs of the European Community, Eastern Europe, the Soviet Union, and even South Africa, the relationship between Japan and America stands out as one of retrogression. This is madness. Yes, there are fundamental differences and legitimate complaints on both sides. The madness is in letting the differences set the tone and agenda of the relationship at a time when a new global era is taking shape. The world is passing through a watershed period of human experience, brought about to some degree by US and Japanese technology. We see the rise of the Pacific Basin as a center of world economic power. The US no longer occupies the predominant political and economic position it held from roughly 1945 to 1973. The Soviet Union may be in its most vulnerable condition in 500 years, with potential consequences that could affect the globe. The world has been linked by an electronic information grid that amounts to an instantaneous global nervous system. Mass migration is a global phenomenon, and ultimately may change not only national demographics, but also the character of national identity. As a world community emerges, the very meaning of nationhood is in flux. In light of such epochal changes, what are Japan and the US saying to each other? "Why don't you open your rice markets?" "Why don't you produce better quality goods?" "Why don't you improve your educational and management systems?" All good questions, but secondary in light of the upheaval the world is going through. In 1776, a few people had a vision that took America to a new concept of liberty. In 1868, a few people had a vision that, in due course, transformed Japan into an industrial giant. Where, now, are the men and women in Japan and the US who will match the dimension of the age with the bigness and breadth of their vision? For 45 years the US-Japan relationship has been subservient to the demands of the cold war. Now that the cold war is over, a historic opportunity exists to refocus the relationship in accordance with the requirements of a new period of world history. George Bush is scheduled to visit Tokyo in January. This visit takes place against the background of the 50th anniversary of Pearl Harbor and Japanese feelings over the president's canceled November trip. Once again, a US administration has jerked the Japanese government around to suit its own domestic political concerns. Some fence-mending needs to be done. BEYOND that, if President Bush can set both nations on a course of cooperative world leadership, it could be the most significant foreign policy achievement of his presidency, eclipsing in the long run the Persian Gulf war and Middle East peace initiatives. So what, practically, should Bush do? The place to start might be to appoint to the highest councils of the State Department or the National Security Council someone who is recognized as a world-class authority on Japan, someone who can fulfill the role Gaston Segur played in the Reagan administration. No such official exists at the moment, and the Japanese understandably interpret this to mean US-Japan affairs are seen as a second-rank priority by this administration. A second step might be to support Japan for a seat on the United Nations Security Council. It's not too much to suggest that the world's premier financial power deserves such a position. The US has been urging Japan to assume greater global responsibility; so how about assisting Japan in gaining the positions of influence which encourage her to exercise such responsibility? Given today's worldwide instability, Japan may be the only other country with a global outreach that could help the US provide some degree of equilibrium. Then consider the environment. Both governments recognize the magnitude and seriousness of global threats such as ozone depletion. Scientists of both countries have outlined environmental agendas that would set the two nations on a cooperative course. There are opportunities for collaboration in Eastern Europe and the Soviet Union. In the US, some Japanese would like to help us develop a high-speed train system on the Eastern seaboard. In both nations, scientific research costs are outstripping national budgets, so combined efforts would save money and might produce superior results. Perhaps most important, as technology continues to shrink the world, Japan and the US should demonstrate how nations with differing historical experiences, cultural traditions, and spiritual beliefs can transcend such gaps and work together for the benefit of the entire globe.