TOKYO (Reuters) - Japan should strengthen the ability of its military 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 defense policy by Prime Minister Shinzo Abe's government, which released an interim report on the issue on Friday. Final review conclusions 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.
The report by a defense ministry panel echoed concerns aired in Japan's latest defense white paper about North Korea's missile and nuclear programs, and China's military build-up and increased activity by its ships and aircraft near disputed islands in the East China Sea - where Japanese and Chinese vessels and planes have been playing cat-and-mouse.
Given Japan's strained ties with China over the tiny islands and Tokyo'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.
The Defence Ministry panel said it was necessary to comprehensively strengthen "the ability to deter and respond to ballistic missiles". Officials denied, however, that this implied Japan would make pre-emptive strikes.
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.
"There is no change at all to our basic policy of exclusively defensive security policy," Japanese Defence Minister Itsunori Onodera told reporters.
"The issue of capability to strike enemy targets surfaces as we discuss what kind of defense measures we can take when multiple attacks have been mounted against our country."
In the Japan-U.S. security alliance, Japan acted as a shield while the United States shouldered the capability to strike enemy bases, he added, but changing security risks needed study.
"Broad-based debate, including one between Japan and the United States, is needed on the issue amid the changing security environment," Onodera said. "Of course, we are not assuming pre-emptive strikes."
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.
Japan has for decades chipped away at the limits 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 defense 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 to Japan's defense policies. Others see it as a more evolutionary development.
Japan already has limited attack capability but to be able to hit mobile missile launchers in North Korea it would need more attack aircraft and intelligence, for which Japan would probably have to rely on 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 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 participate in international projects and take new steps if needed, the ministry said in its report.
Clearer guidelines as to what equipment companies may sell and to whom could help companies 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 defense against incursions from the south, site of the islands row with China.
Additional reporting by Kiyoshi Takenaka; Editing by Clarence Fernandez