Editorial Board

Should Japan Rearm? Discuss.

Prime Minister Abe needs to lead a debate about how respond to the missile threat.

Cause for worry and debate.

Photographer: Kazuhiro Nogi/Getty Images

Outraged by Tuesday’s North Korean missile test, Japanese Prime Minister Shinzo Abe immediately called for an emergency meeting of the United Nations Security Council. Japan needs to have an equally urgent debate at home.

The missile, which buzzed the island of Hokkaido before crashing into the sea, was especially provocative because North Korea had previously only sent satellite-launching rockets over Japan. Judging by past experience, success will embolden the North to conduct similar tests, raising the possibility that a missile could go awry or disintegrate over a Japanese city. Japan and the U.S. would have to decide whether to shoot them down, increasing the risk of wider hostilities.

Worse, it’s unclear whether Japan’s current missile defenses are even up to that task. It currently deploys ship-borne interceptors, designed to shoot down intermediate-range ballistic missiles, and land-based Patriot batteries, which can take out more primitive missiles or falling debris. It’s considering adding more powerful land-based interceptors as well, but those systems would be costly and might not be able to stop a barrage of simultaneous launches.

Abe’s task now is to build support for stronger measures. For years, politicians and policy wonks have debated whether Japan’s pacifist constitution allows offensive action under certain circumstances -- say, to take out a North Korean missile on the launch pad moments before liftoff. The consensus is that it does, under very limited circumstances. But it would require weaponry, such as Tomahawk cruise missiles, that would dramatically increase Japan’s warmaking capacity.

Abe needs to make the case for the fast development of such a capability. And he needs to be clear about the circumstances under which it would be used.

The prime minister needs to be similarly honest about his long-running push to revise Japan’s constitution, including its clause renouncing war. He says the changes he’s proposing would do no more than legitimize Japan’s existing Self-Defense Forces. But his past statements and links to hard-right groups have raised legitimate doubts about his intentions.

Japanese are conflicted about such big changes to their constitution, even as three-quarters of them say they would favor either preemptive strikes or a swift counterattack if North Korea were about to launch a missile toward Japan. Abe owes them an open debate in which all sides get a full hearing.

Such a debate would also help ease opposition outside Japan, most notably in South Korea, which has long been sensitive to any suggestion that its former colonial overlord might rearm. For the two neighbors to establish a credible deterrent, they’ll need to coordinate missile defenses, share intelligence and operate seamlessly with U.S. forces. Tensions between them would undercut any good Japan’s new capabilities might otherwise do.

China, of course, is unlikely to view any increase in Japan’s offensive military capabilities -- or its missile defenses, for that matter -- with equanimity. Instead of lashing out, however, leaders in Beijing might consider whether they’ve done everything they can to mitigate the North Korean threat. A more heavily armed Japan is just one of the costs of their refusal to do so.

    --Editors: Nisid Hajari, Michael Newman.

    To contact the senior editor responsible for Bloomberg View’s editorials: David Shipley at davidshipley@bloomberg.net .

    Before it's here, it's on the Bloomberg Terminal.