Photo/IllutrationA JASSM-ER long-range cruise missile is released from a bomber. (Captured from Lockheed Martin Corp. website)

The Defense Ministry will seek an additional 2.2 billion yen ($19 million) in initial budget requests for fiscal 2018 to cover the acquisition of long-range cruise missiles.

Under Japan's "defense only" national policy, the government until now has refrained from extending the cruising range of missiles used by the Self-Defense Forces. This restraint was also due to fiscal strictures and aimed at averting a fruitless arms race.

The Defense Ministry's stated reason for breaking with tradition is that the new missiles will defend Japan's remote islands and Aegis destroyers deployed against North Korean missiles. As such, the purpose is strictly for national defense, the ministry said.

True, Japan's security environment is severe, and SDF defense capabilities need to be reviewed constantly.

The U.S-made missiles to be acquired for Air SDF fighters have a range of 900 kilometers. Fired from over the Sea of Japan, they can reach all corners of North Korea.

We do not accept that such long-range missiles are necessary. Also, it exceeds the bounds of Japan's "defense only" policy.

Acquiring them could represent the first major step toward building up the nation's offensive capability to attack enemy missile bases.

In this regard, the government's traditional thinking was that a strike could be considered "within the legal theory of defense," if and only "no other options exist."

In 2005, the director-general of what was then the Defense Agency told the Diet, "The government is not considering acquiring munitions intended for attacking enemy bases, including long-range cruise missiles for that purpose."

Under Japan's national security policy, the U.S. armed forces have always served as the "halberd" and the SDF as the "shield."

If the rest of the world perceives the Defense Ministry's latest decision as a departure from that traditional stance, we fear it will alarm Japan's neighbors and negatively impact the regional security environment.

Despite grave fiscal problems, the Abe administration has doubled defense spending for five years in a row. And with the United States under President Donald Trump escalating U.S. arms exports to its allies, there is no guarantee that once Japan oversteps the bounds of its defense-only policy, Washington won't relent in its drive for Japan to purchase more costly weapons.

One thing that cannot be overlooked is that this shift in defense policy was announced abruptly, without prior explanation to the public or the Diet.

The 2.2 billion yen for missile acquisition was not included in the government's budget plan this past summer. This additional sum came up just before the conclusion of the extraordinary session of the Diet earlier this month.

A review of the National Defense Program Guidelines and the next Midterm Defense Buildup Plan will begin in earnest next year. Within the ruling Liberal Democratic Party, there already are loud calls for a sharp defense budget increase and the acquisition of offensive capabilities against enemy bases.

The Abe administration's piecemeal changes to the national security policies are dangerous. We call for a thorough debate on this and related issues in the coming regular session of the Diet that starts in January.

--The Asahi Shimbun, Dec. 13