Top Japanese military officials are quietly but firmly insisting they want the U.S. to release the F-22 to compete for the air force's F-X fighter program, and are adamant about fielding the most advanced air-combat technology available.

Tokyo wants a stealthy fighter equipped with an active electronically scanned array (AESA) radar for cruise missile detection and wide-band data links to push additional information into Japan's increasingly sophisticated air defense system. For the moment, only the Lockheed Martin F-22 Raptor offers all these features.

Access, however, is far from assured, with the U.S. Congress requiring over-sight and approval of any plan for foreign sale of the stealth fighter. The U.S. has been trying to pitch either an upgrade of in-service designs (such as F/A-18E/Fs or F-15Es equipped with advanced, small-target, long-range radars) or the Lockheed Martin F-35 Joint Strike Fighter for the F-X program. The primary driver for the F-X requirement remains air superiority--which includes cruise missile defense--for which Tokyo wants the F-22.

Japan also faces the cost of integrating an anti-tamper kit on key technologies, including hardware and software, on the F-22. Estimates range from $600 million to $1.2 billion. Key software that would be protected, for example, manipulates and integrates the advanced, cruise missile-detecting radar and long-range electronic surveillance array, as well as the aircraft's other target-detection and analysis sensors.

U.S. aerospace industry officials say the cost would be no more than $1 billion--if it means integrating a new common processor--and could be "far less," depending on how much or little the U.S. determines must be protected, according to a study done when Australia was considering buying the F-22.

Were Washington to nix release of the F-22, then European manufacturers would try to capitalize on the opportunity. The Eurofighter Typhoon is already being pitched for Japan. A variant fitted with an active "E-scan" radar array and the Meteor rocket-ramjet radar-guided air-to-air missile would offer a capable air superiority platform.

One way to defray some of the potential cost would be if the U.S. Air Force also buys the new computer as an F-22 upgrade. Moreover, if Japan buys the aircraft, it would reduce the cost of F-22s to the U.S. Air Force and perhaps let it acquire a few more of the advanced fighters, a crucial need if the F-35 JSF program slips.

Release of the F-22 is becoming a point of pride with the Japanese, who provide the U.S. forward bases in the region as well as dispersal and rapid deployment options in case of a military confrontation or natural disaster, say U.S. officials. Exporting the technology isn't a concern for U.S. combat pilots, since software packages for U.S. versions of the aircraft will always contain extra capabilities. In addition, U.S. military officials are privately asking administration and senior Pentagon civilians to reconsider the export restrictions, at least for Japan.

"I'm aware the Japanese are interested in the F-22," Gen. Peter Pace, chairman of the Joint Chiefs of Staff, told Aviation Week & Space Technology last week. "I'm also aware of our concerns about what we export and don't export of our high technologies. The Japanese are very close friends. We're committed to protecting Japan, so we'll work our way through it. We all need to be concerned about both ballistic and cruise missile defense. It's something that we . . . need to work on."

There also seems to be a Pentagon precedent for meeting Japan's high-tech needs.