America's relations with Japan are in a jumble on a number of fronts. The real problem, which nobody wants to address openly, is that 65 years after the end of World War II the United States still has some 50,000 troops in Japan.

America is not very good at ending wars, particularly, it seems, those that it wins. In addition to the troops in Japan, there are 56,000 remaining in Germany, long after the end of World War II in Europe and two decades after the end of the Cold War. The United States maintains 28,000 troops in South Korea, 57 years after the end of the Korean War. The United States even continues to maintain a thousand troops in Cuba, which have been there since the 1898 Spanish-American War. (Residual troops will be a question worth watching in the wake of the Iraq war.)

These various troop presences are usually justified in the name of grand strategy, although the argumentation becomes tortured. There is no argument for stationing troops in Cuba. Germany, Japan and South Korea are strong, wealthy, democratic states. Japan remains the world's second largest economy. Germany is the fourth, and firmly ensconced in NATO in terms of its defense.

Still, we are there, in spite of the financial cost, our country's other needs and the demand for our troops in Afghanistan and Iraq. So, why?

Some say the American military wants to keep its force levels up and deployed across the globe to protect our interests. That raises again the question of why, particularly given the rapid deployment of troops made possible by today's communications and transportation capacities.

Defense contractors, who contribute generously to the political campaigns of presidents and members of Congress, certainly profit from the current level of U.S. deployment across the world and wouldn't like to see it trimmed.

A pettier argument says the Pentagon wants to continue to have lots of commands and generals. That was certainly an element in the creation in 2008 of an Africa Command, headed by a new four-star general based in Europe.

U.S.-Japanese relations now are bedeviled by a number of problems. It is ironic that this is the case just as HBO launches what will be a widely watched 10-week serial on World War II in the Pacific. The first episode on Sunday tried to tread a fine line between demonizing the Japanese for their approach to the war and presenting them as a fully human enemy, with wives and children at home.

The proximate cause of the disruption in U.S.-Japanese relations was the replacement last year of the Liberal Democratic Party, which had ruled Japan almost continuously since 1955, by the Japanese Democratic Party. It isn't that the JDP is anti-American. It is rather that, as a new party in power, it is quite normal for it to look sharply at some of the basic principles that governed Japanese policy during the 53 years of LDP rule.

One of these was Japan's relationship with the United States. An integral part of that -- perhaps the central pole of it -- is the presence of the U.S. troops in Japan. That presence is the cornerstone of a sense on the part of the Japanese that the United States remains fundamentally responsible for their national security.

There is friction on an interpersonal basis. When I was stationed at the American Embassy in Reykjavik, Iceland, one of the issues between the United States and Iceland was the presence of some 5,000 U.S. troops at an airbase on the island. To avoid problems, the American service members were discouraged from traveling around the country. In Japan, most of the U.S. troops are on the island of Okinawa, where, from time to time they are involved in accidents; murders; rapes; air, water and noise pollution; and other sources of misunderstanding.

The current focus of disagreement between the two countries militarily is the question of relocating a Marine base on the island of Okinawa. According to a 2006 agreement, some of the Marines are scheduled to move to the U.S. island of Guam in 2014, at a cost to the Japanese of $6 billion. (The U.S. troop presence in Japan costs its government an estimated $4 billion a year.) The JDP government also annoyed the administration of President Barack Obama recently by ending Japan's 8-year-old refueling mission in Afghanistan.

Another point of sensitivity are the "secret treaties," which dealt inter alia with the introduction into Japanese waters of nuclear weapons on U.S. warships, in violation of Japan's no-nuclear policy, which began with the U.S. nuclear attacks in 1945 on Hiroshima and Nagasaki.

All in all, the new Japanese government has its eye on shifting power relationships in East Asia. China has already passed the United States as Japan's largest trading partner. The U.S. Congress' dogging of Toyota and its president last month probably didn't help, particularly since the U.S. government is an important owner of Toyota rivals General Motors and Chrysler. China, by contrast, sent its heir-designate, Vice President Xi Jinping, to Japan in December for a very visible visit. Japan's potential enemies in the region, China and North Korea, are, in fact, now moving into a different relationship with it, particularly if China is to be considered to have North Korea more or less under its control.

Rather than let the post-World War II marriage between the United States and Japan drift further onto the rocks, the Obama administration might think about being realistic and moving the relationship to a new stage, proposing a phased withdrawal of U.S. forces from Japan. There would be logic in such a proposal from an American point of view: It would save money, permit more concentration on U.S. domestic needs and move us toward stationing troops only where they are needed, as opposed to where they have been forever.

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