OVER THE EAST CHINA SEA -- In a delicate ballet 25,000 feet above the open sea, four Japanese F-15s pull up to a U.S. Air Force tanker, the red disk of the standing sun shining from their fuselage and wings. One by one, they maneuver into range of the tanker's refueling boom, hold their position, then dip their wings and vanish.
American military planners say it's the look of the future -- a deeply interwoven relationship with a credible Japanese ally ready to deploy overseas and share the burden of keeping the peace in a volatile region.
To the American crew, the mock refueling is just another day's work.
?The skill level is the same; the planes are the same,? said boom operator Tech. Sgt. Michael Webster of Greenfield, Mass. ?It's basically just like working with our own people.? The only difference, he says, is the language, but both sides manage with English.
In Washington, it's called ?interoperability,? and it's a top military priority. With its own forces engaged in Iraq and elsewhere, the United States needs to strengthen its alliances and draw on its friends for whatever support it can get. And since the end of World War II, Japan has been Washington's best friend in Asia.
But the idea of a beefed-up Japanese military doesn't resonate well through the region.
As the two-week refueling exercise was being carried out late last month, relations between Japan and neighboring China were plunging to their lowest point in years, largely over Japanese wartime aggression that left millions of Chinese dead, and over Tokyo's bid for a permanent seat on the U.N. Security Council.
There is no consensus in Japan, either.
Some Japanese leery
Negotiations on a broad reworking of the military alliance with Washington are reportedly bogging down because the government is divided over just how far Japan should follow Washington's call.
The bigger question is whether Japan should even be a military power.
The U.S.-led occupation forces disbanded Japan's military after World War II and helped write a constitution that barred Japan from using ?the threat or use of force as a means of settling international disputes.?
Washington soon realized it needed to build an ally to counter communism in Asia, and Japan passed a law in 1954 that paved the way for establishing its Self-Defense Forces. Though the decision was denounced by many who saw it as unconstitutional, the government argued that the military force is legal because it is strictly defense-oriented.
That argument is becoming hard to sustain.
Japan has more than 240,000 active-duty troops and an annual defense budget bigger than Britain's. Its air force has more than 160 F-15s and its spy satellites keep watch on North Korea.
Prime Minister Junichiro Koizumi, who advocates a constitutional change to free up the military, has pushed the envelope even further, sending hundreds of soldiers to southern Iraq for humanitarian activities and more to Southeast Asia to provide tsunami relief.
?Japan is America's only reliable partner in Asia, and Washington wants Japan to make a big contribution in its efforts in the region,? said Takehiko Yamamoto, professor of international relations at Waseda University in Tokyo.
Mr. Yamamoto said Tokyo, for its part, wants to bolster its troops largely because of the perceived threat from China and North Korea, which is developing nuclear weapons and has missiles that can deliver them to Japan.
Fighter scrambles rise
The Japanese Defense Agency announced recently that its fighter jets scrambled 13 times last year in response to Chinese military aircraft approaching Japan's airspace, up from only twice in 2003. And on May 1, North Korea apparently test-fired another missile into the East Sea/Sea of Japan. However, Japanese and South Korean officials said it was a small missile unrelated to anything nuclear.
Mr. Yamamoto said the political constraints on Japan's military posture have eased. ?Collective security used to be seen as unconstitutional. But it seems the Japanese government believes it need only reinterpret -- not change -- the constitution to justify its policy shifts.?
Two areas have long been taboo: the development of nuclear weapons and the acquisition of aircraft carriers or other means of projecting power overseas.
The nuclear ban, driven by memories of Hiroshima and Nagasaki, remains firm.
But the Japanese Defense Agency announced plans in 2001 to buy a 13,000-ton destroyer with a flight deck for anti-submarine helicopter operations. Opponents called it a mini-aircraft carrier.
The day when Japan refuels American F-15s, meanwhile, may not be far away. In two years, Japan's first air tanker, a Boeing 767, will be delivered to a military airfield in Nagoya, central Japan.
?We want them to be able to do pretty much whatever we can do,? said Lt. Col. Chris Comeau, commander of the 909th Airborne Refueling Squadron at Kadena Air Base on Japan's southern island of Okinawa, where the American tankers are based.
?They want to be bigger and better, and we want to help them,? said Col. Comeau. ?Wouldn't it be cool one day to have Japanese tankers refueling American F-15s??
Capt. Shinya Akiyoshi, a test pilot who is among several candidates to be on the Japanese tanker's first crew, said it will serve two important goals: keep Japanese fighters in the air longer and, therefore, more rapidly responsive to intruders, and cut down on noisy, potentially dangerous landings and takeoffs in densely populated areas.
Capt. Akiyoshi, who participated in the refueling training, noted fears the tanker could also be used to extend the striking range of Japanese fighters. But he said that shouldn't stop Japan from doing what it feels it needs to do.
?Our neighbors are sensitive,? he acknowledged. ?But we have to keep telling them that this is about our national defense. We don't intend to use our fighters for any other purpose.?