Japan will lead search for middle ground. (Japan's stand on global warming)

TOKYO - While the United States debates what stance to take toward a global-warming treaty, the Japanese government has staked out its position.

Mediator.

As host of the Kyoto conference in December, Japan seems determined to find a middle ground among nations whose positions on global warming vary radically.

Japan's proposal, tendered last week, calls for reducing worldwide greenhouse gases by 5 percent from 1990 levels. That is nowhere near as stringent as the 15 percent cut favored by the European Union.

Indeed, the European Union had indicated to Japan that it would consider anything less than a 5 percent target unacceptable.

Speaking in …