Japan is evolving away from a wall flower national-security policy. Once restricted to defending the home islands, Tokyo's military is playing a heftier role in global affairs than at any time since World War II.

Today, Japan's armed forces are supporting the United States in Afghanistan with a flotilla of ships in the North Arabian Sea. And in Iraq, Tokyo has over 500 soldiers in the southern city of Samawah.

Japan recently hosted a multinational exercise aimed at interdicting weapons of mass destruction from an unknown country (read: North Korea). And in some muscle-flexing late last week, Japanese ships and planes chased an unidentified (read: Chinese) nuclear sub from Japanese territorial waters in the East China Sea.

These security operations are unprecedented in Japan's post-WW II history. But this is no resurgence of 1930-40s imperial Japanese militarism, though Tokyo's new assertiveness will alarm some in the region. Japanese Prime Minister Junichiro Koizumi is merely overhauling Japan's national security in ways that will benefit itself, the U.S.-Japan alliance and international security.

Japan's 1947 "peace" constitution (written during the U.S. occupation) renounces war as a "means of settling international disputes." And when it reconstituted its armed services in 1954, it gave them non-threatening names. So there's no Japanese army - in title anyway. Japan has a Ground Self-Defense Force. The same goes for the air force and navy.

For half a century, Japan relied on an American security umbrella for its protection, and checkbook diplomacy to win friends and influence the world community.

But being the world's ATM proved deeply disappointing - and even downright humiliating. During the 1991 Gulf War, Japan was harshly criticized for contributing cash ($13 billion) instead of troops to the international coalition opposing Saddam Hussein's Kuwaiti invasion.

And new, burning concerns - such as North Korea's nuclear program (and ballistic missiles) and China's prodigious military buildup - caused security-sleepy Japan to sit up and take notice.

Tokyo realized that it had to do something about its increasingly tough neighborhood. So it undertook a defense strategy review. The review won't be completed until year's end, but here's how it's likely to come out:

•  Self-Defense Forces: In a Pentagon-like transformation, the SDF will develop lighter, more deployable forces for operations at home and abroad. International peacekeeping will become a primary SDF duty - possibly freeing up U.S. forces for other "hot" missions.

Japan will also shift the SDF's focus south toward the Korean peninsula and China, finally dispensing with its Cold War focus on a Soviet invasion from the north. And Tokyo will build power-projection weapons systems such as naval helicopter carriers, destroyers and air-air refueling aircraft. (Nukes will remain taboo.)

•  Missile Defense: Caught off guard by a 1998 North Korean missile test shot over Japan, Tokyo has finally decided to develop and deploy a joint missile-defense system with the United States. Japan's decision to deploy sea- and land-based missile defense will strengthen the bilateral alliance, adding to regional stability undermined by the growing threat of Chinese and North Korean ballistic missiles.

(The disposition of the 47,000 American troops stationed in Japan will also change under the Pentagon's Global Posture Review, including a likely relocation of some American Marines off Okinawa.)

China and North Korea are sure to cry bloody murder over Tokyo's national-security policy changes: All Asia has grim memories of Japan's 20th-century militarism. But changes in Japan's defense policy wouldn't be necessary if those two powers didn't pose growing threats to Tokyo's security.

Younger Japanese don't feel responsible for Japan's World War II transgressions, they see the world without chauvinism and want Japan to be a normal nation. Fortunately, any evolution in Japanese security policy will be open, transparent and democratic. Once formulated, Tokyo must do its best to explain its new defense policy to its neighbors.

For over 50 years, the U.S.-Japan alliance has been the anchor of American security interests in the Pacific. Tokyo can - and should - do more to stabilize regional flashpoints (e.g., the Taiwan Strait and Korean Peninsula) as well as contribute more broadly to international security.

And in addition to managing North Korea and guiding China's rise, the U.S.-Japan alliance should evolve into a true global partnership. With inspired leadership and increased cooperation and capability, the alliance will be ready to deal with 21st-century challenges both in Asia and across the globe.

Peter Brookes is a Heritage Foundation senior fellow. E-mail: [email protected]