Japan should beef up its military's ability to deter and counter missile attacks, including the possible acquisition of the ability to hit enemy bases, the Defence Ministry said, but officials denied this would be used for pre-emptive strikes.
The proposal - Japan's latest step away from the constraints of its pacifist constitution - is part of a review of defence policy by Prime Minister Shinzo Abe's government, an interim report on which was released on Friday. The final conclusions of the review are due by the end of the year.
The hawkish Abe took office in December for a rare second term, pledging to bolster the military to cope with what Japan sees as an increasingly threatening security environment including an assertive China and an unpredictable North Korea.
Given Japan's strained ties with China over disputed isles and Japan's wartime history, Beijing could react strongly to the proposals, which come after Abe cemented his grip on power with a big win in a weekend election for parliament's upper house.
Article 9 of Japan's constitution, drafted by U.S. occupation forces after the country's defeat in World War Two, renounces the right to wage war and, if taken literally, rules out the very notion of a standing army. In reality, Japan's Self-Defense Forces are one of Asia's strongest militaries.
The Defence Ministry said in the report it was necessary to comprehensively strengthen "the ability to deter and respond to ballistic missiles". But in a sign of the sensitivity of the issue, a ministry official denied that this implied Japan would make pre-emptive strikes against enemy bases.
"Our country is building up ballistic missile defence ... but North Korea and other countries are improving their capabilities," a ministry official told reporters.
"It is necessary to consider whether we should have the option to strike an enemy's missile launch facilities," he said. "But we are not at all thinking about initiating attacks on enemy bases when we are not under attack."
The line between the ability to hit enemy targets and make pre-emptive strikes is primarily political and philosophical, and Japanese officials typically avoid the latter term. But acquiring the capability for pre-emptive strikes against enemy missile bases would be difficult and costly, experts said.
"Offensive capability can be used for pre-emptive purposes," said Narushige Michishita, a professor at the National Graduate Institute of Policy Studies. "In reality, we will not be able to. We are just too far away."
STRETCHING THE LIMITS
Japan has for decades chipped away at the restrictions of Article 9. It has long said it has the right to attack enemy bases overseas when the intention to attack Japan is evident, the threat is imminent and there are no other defence options.
But while previous administrations shied away from acquiring the hardware to do so, Abe's Liberal Democratic Party in June urged the government to consider acquiring that capability against missile threats.
Some experts say acquiring more substantial offensive capability would be a fundamental change for Japan's defence policies. Others see it as a more evolutionary development.
"It is part of an evolution towards having a more normal military posture," said Richard Samuels, director of the MIT-Japan Program at the Massachusetts Institute of Technology. "Normal means being able to defend yourself."
Japan already has limited attack capability but being able to hit mobile missile launchers in North Korea - the most likely target - would require more attack aircraft and intelligence for which Japan would probably need to rely on its ally, the United States, experts said. Hitting missile bases in mainland China would be an even bigger stretch.
Whether Japan, with a huge public debt, can afford the bill, is another big question.
Measures to strike enemy missile facilities include attacks by aircraft or missiles and sending soldiers directly to the site, the Defence Ministry official said, but he added it was too early to discuss specific steps.
The ministry also said it would consider buying unmanned surveillance drones, create a force of Marines to protect remote islands, such as those disputed with China, and consider beefing up the ability to transport troops to far-flung isles.
Japan should also review its self-imposed ban on arms exports that has already been eased to let Japanese contractors take part in international projects and take new steps if needed, the ministry said in its report.
Clearer guidelines as to companies may sell and to whom could help Japanese defence contractors such as Mitsubishi Heavy Industries Ltd, Kawasaki Heavy Industries Ltd, and Fuji Heavy Industries Ltd seek business overseas.
Support has grown in Japan for a more robust military because of concern about China, but opposition also remains.
Japan last updated its National Defence Programme Guidelines in 2010, when the Democratic Party of Japan was in power.
Those changes shifted Japan away from a Cold War legacy of defending northern areas to a more flexible defence against incursions from the south, the site of the row with China over tiny, uninhabited islands.