Japan must act to stop the decline in its regional and international standing, a former Defense Department official warned Thursday.

"The erosion of Japan's international, regional position has begun," said Richard Lawless, deputy undersecretary of defense for Asia and Pacific security affairs.

"If this marginalization process of Japan is not addressed openly and . . . proactively, the relative decline will accelerate," he said, adding "Japan will never find itself in a place where it used to be" without visible action.

"Few in Japan share my concern," he said.

Lawless said in a speech that Japan's decline is partly attributable to the global financial crisis, which has forced many leading Japanese companies to fall into the red.

He also pointed out inaction on the part of Japanese policymakers in relation to a plethora of challenges, most recently the response to piracy off Somalia.

It took China "about 10 seconds" to decide to participate in an antipiracy mission there, but Japan spent a tremendous amount of time before deciding this week to send two destroyers on a similar mission, Lawless said.