Since their establishment in 1954, the Self-Defense Forces have never had to be mobilized to defend Japan from attack.

The forces over the last five decades of Cold War peace have instead often engaged in nonmilitary tasks as disaster relief.

SDF elements have participated in international missions since the early 1990s, but their roles have been strictly limited to logistic support and humanitarian aid work.

With Friday's announcement of the new National Defense Program Outline, however, the SDF is on the verge of being transformed into a military ready to go to war in the event of a terrorist or missile attack.

The forces are also expected to play a greater role in improving international security.

"It's a time of operation," Hajime Massaki, chief of the Joint Staff Council, said Thursday. "Up to now, we have engaged in training to serve as a deterrence. But from now on, our capabilities will be tested."

By specifically naming China and North Korea as threats to national security and pledging to revamp the SDF to counter them, Japan's security policy is becoming that of a normal state, observers say.

Massaki said, "We are going to be on the same level (militarily) as other nations."

Defense experts say behind the defense policy overhaul lies the strengthening of the Japan-U.S. security alliance over the past decade.

Since the last review of the National Defense Program Outline in 1995, the bilateral alliance has seen major changes that have required Japan to take on a greater role in its security.

In 1996, then Prime Minister Ryutaro Hashimoto and then U.S. President Bill Clinton agreed to expand the scope of the alliance to cover security in the Asia-Pacific region. The 1960 Japan-U.S. security pact covers Japan and the Far East.

The Japan-U.S. defense cooperation guideline, updated in 1997, and subsequent bills approved by the Diet call for the SDF to provide logistic support to U.S. forces should a threat to Japan's peace and security occur in "areas surrounding Japan."

More visible changes were observed after the Sept. 11, 2001, terrorist attacks on the United States.

Maritime Self-Defense Force ships have been sent to the Indian Ocean to provide fuel for U.S. and other nations' warships involved in the war on terrorism being waged in Afghanistan, and Ground Self-Defense Force troops have been in war-torn Iraq since January on a humanitarian mission.

Japan is also among several nations participating in the U.S. missile defense project.

"It is a review of what Japan can do in line with the new Japan-U.S. security alliance under a new security environment," Toshiyuki Shikata, a retired GSDF general who is now a law professor at Teikyo University, said of the latest security policy revisions.

The alliance with the U.S. is the foundation of Japan's defense policy. Should Japan be attacked, it is allowed to fight back until the U.S. military comes to its aid.

The war-renouncing Constitution, which ostensibly prohibits a national military force, has been interpreted to allow Japan to use forces for defense.

Chief Cabinet Secretary Hiroyuki Hosoda stated Friday: " Japan will maintain basic defense policies defined by the Constitution."

However, some the key principles that have guided Japan's postwar, self-defense-oriented policy were effectively scrapped in the new National Defense Program Outline.

Japan's arms exports ban -- announced in 1967 with the aim of not triggering or aggravating international disputes -- is being eased to allow Japan to participate in the U.S. missile defense project.

The traditional concept of a "basic defense force," which has served as a restraint to a military buildup, was replaced by a new one that stresses quick deployment capabilities.

The overseas dispatch of troops, once considered taboo, is being encouraged to increase.

"Contradictions between the Constitution and Japan's security policy are reaching their limit," said Tetsuo Maeda, a security expert and professor at Tokyo International University.

Under the new security policy, the SDF will grow out of its role as a purely defensive force to a force ready for quick deployment -- both to support U.S. military operations and to defend Japan's interests, he said.

Highlights of defense buildup plan

Efforts will be made to improve the capability of Aegis destroyers and Patriot surface-to-air guided missiles to cope with a ballistic missile attack.

A new unit, 4,000- to 5,000-strong, to be based at the Ground Self-Defense Force Asaka Garrison straddling Tokyo and Saitama Prefecture will command mobile units and special forces in emergencies.

The Maritime Self-Defense Force will revamp its escort elements into eight divisions, each consisting of four destroyers.

New MSDF patrol planes will be deployed to replace the P-3Cs.

The Air Self-Defense Force will introduce an in-flight refueling squadron at the ASDF base in Komaki, Aichi Prefecture, that will provide fuel for international and defensive missions.

It will also develop new long-distance transport aircraft and a new fighter to replace the F-4EJ Phantom.

The SDF will create an education unit for international missions and set up a joint chiefs of staff and promote integrated operations of its three branches.