May 14, 2007: The U.S. and Japan have agreed to exchange vital intelligence information on an ongoing basis. Japan will provide the United States with data from its BADGE (Base Air Defense Ground Environment) system, while the U.S. will link Japanese air defense headquarters with data about North Korea missile launches gathered from American spy satellites and patrol aircraft.

The BADGE system includes data feeds from 28 air defense radars, as well as sensors of aircraft in the air. BADGE provides the most accurate picture of what's in Japanese air space. Japan has long rebuffed American requests to share BADGE data on a regular basis. The U.S. gets access to BADGE during joint training exercises (because in wartime, the U.S. would have regular access to BADGE), but the Japanese were touchy about having the Americans looking over their shoulders, so to speak, all the time.

But Japan is very concerned about North Korea ballistic missiles, and the increasingly unstable North Korea government. Japan fears that things might unwind quickly in North Korea, and missiles could get launched at Japan. Now that Japan is deploying American Patriot anti-missile missiles, it wants the most warning of a North Korean launch possible. Japan has its own sensors watching for North Korean missile launches, but the addition of American sensor data is reassuring.

This cooperation enables intelligence analysts from both countries to better monitor what's going on in the air around Japan, which occasionally includes intrusions by Chinese and Russian aircraft.