YOKOTA, Japan — The "Dear Leader" of North Korea, Kim Jong Il, inadvertently has added urgency to U.S. plans to realign its military forces in Japan, to Japan's intent to make its forces more relevant, and to both seeking to increase their capabilities by operating more closely together.

In the weeks following the North Korean launch of seven missiles into the sea between the Koreas and Japan on July 4, Lt. Gen. Bruce Wright, the Air Force officer who commands American forces in Japan, said there had been "a monumental change" in Japanese attitudes toward transitions already under way. Japanese officers, queried separately, agreed.

Before, negotiations had been moving along but had run into obstacles due largely to political pressures within Japan. Opposition focused on local issues such as noise from aircraft, crowding as residential areas grew up around once-remote U.S. bases, and friction between Japanese and Americans in Japan who knew little of each others' culture.

Those issues have not been entirely swept away, but as a staff officer at this U.S. air base west of Tokyo said, "Japan is on the cusp of major changes in security policy." The Japanese, for instance, have asked the U.S. to accelerate delivery of Patriot anti-missile batteries to Japan.

Speculation that Kim Jong Il might order a North Korean nuclear bomb test has given more impetus to the revisions. An unknown factor, however, is the effect of a potential U.S. reduction or withdrawal of troops from South Korea, across a narrow strait from Japan. In U.S. military strategy, Japan and Korea comprise a single area of operations.

To nudge these changes along, Adm. William Fallon, who leads U.S. forces in Asia and the Pacific from his headquarters in Hawai'i, visited Japan two weeks ago. He met with Chief Cabinet Secretary Shinzo Abe, the front-runner to succeed Prime Minister Junichiro Koizumi later this month, and other political and military leaders in Tokyo.

Further, the admiral flew to Japan's southwest island of Kyushu to meet with Lt. Gen. Naoto Hayashi, who commands Japan's Western Army with headquarters in Kumamoto, and Vice Adm. Yoji Koda, commander of the Japanese navy's regional district with headquarters in Sasebo. The U.S. Navy has a base next door.

The weight of Japan's small but modern armed force is gradually being shifted from Hokkaido, the northern island, where its Northern Army's mission was to repel a possible Russian invasion. Today, Japan sees a near-term threat from North Korea and a longer range threat from China — and Kyushu is closer to both than is Hokkaido.

Said a Japanese officer in the Western Army: "We are the ones out front now." If Japan were to deploy troops abroad, such as rotating 10 contingents of 600 soldiers each to Iraq, they would most likely come from the Western Army.

Time lines have been set for changes between now and 2014 that will add up to a new look for both U.S. and Japanese forces.

In 2008, a forward element of 200 soldiers from the U.S. Army's I Corps is to move from Fort Lewis, Wash., to Camp Zama, southwest of Tokyo, to prepare communications, a combat command center and support facilities for a joint task force headquarters of 500 more soldiers if a contingency arises.

That forward element is to be joined by the Japanese army's Central Readiness Force by 2012. The two units will be charged with preparing complementary operational plans for their respective ground troops.

Here at Yokota, the Japanese Air Defense Command will move from nearby Fuchu by 2010. A joint command center was set up last December, tested in exercises during the winter, and was operative on July 4 gathering intelligence on the North Korean missile shoot. One missile exploded shortly after launch, prompting an American quip: "Six Scuds and a dud."

On the Japanese side, a lack of coordination and joint operations among the armed forces has long been a glaring weakness. Seeking to rectify that, Japan established a Joint Staff Office in March along the lines of the U.S. joint staff in the Pentagon. Japanese and American officers alike said, however, that Japan has far to go to acquire the habit of joint operations.

General Wright said the joint coordination center was intended to speed communications among Japan's Joint Staff Office, his headquarters at Yokota, and the U.S. Pacific Command in Hawai'i. "Working together has tremendous power," he said in a recent TV interview. "One plus one equals much more than two."

Richard Halloran is a Honolulu-based journalist and former New York Times correspondent in Asia. His column appears weekly in Sunday's Focus section.