Prime Minister Junichiro Koizumi recently told the Japanese House of Councilors that Japan would be under no obligation to use a proposed missile defense system to shoot down missiles aimed at its allies, including the United States.

“The purpose of our country’s missile defense is to intercept incoming missiles targeting Japan,” he said. “We are not thinking of dealing with other missiles targeting our allies.”

The United States, on the other hand, is obliged to come to defend Japan against attack.