Japan’s new Prime Minster Shinzo Abe is generally seen as a hawk, in the mode of former PM Junichiro Koizumi. But he’s not yet seen as being as strong a leader as the flambouyant Koizumi was. In one sense that’s good–Koizumi was very good at managing relations with the Bush administration, not so good at managing ties to China and South Korea. Abe’s ascent was already seen as a chance for Japan to stay in the US camp while mending fences with those two neighbors. That may help keep the international response to North Korea’s nuclear test focused on the core issue. We’ll probably know very shortly what kind of leader Abe is capable of being, as he is inheriting the worst foreign policy crisis Japan has faced in decades. North Korea threatens Japan nearly as often as it threatens the US; Japan has to see a nuclear armed Kim Jong-Il as an intolerable threat. Japan may find itself leading the world in taking on the threat from a nuclear-armed North Korea.

Abe has already formed a task force to discuss the North Korea issue.

This will become relevant to Japanese and international discussions very soon, though even its current language doesn’t preclude Japan from acting against North Korea in pre-emptive self-defense. It’s relevant to Japan’s overall military posture, which is currently purely defensive. That’s likely to change.

In the medium term, Japan will undoubtedly return to being a military power. That won’t take long. Japan will probably become a more assertive power in the Asian sphere, which will have the beneficial effect of providing a counter to the Chinese. Japan’s return to military power will scare the hell out of several countries in the region including China, so we can reasonably expect an arms race to kick off in the next year or so. Japan will go nuclear, followed by South Korea. Others in the region including Taiwan will follow as quickly as they can, unless North Korea is strongly punished and is no longer seen as a threat.

Tonight’s test puts China in the spotlight, as North Korea’s chief enabler and benefactor. Outside North Korea itself, the country most responsible for this turn of events is China for failing to rein North Korea in years ago.

It’s important to keep a couple of things in mind. As far as anyone outside North Korea knows, North Korea has yet to build a working ICBM. North Korea has short and medium range missiles capable of hitting South Korea and Japan, though. North Korea also has yet to miniaturize a nuclear weapon so that it can put one on even a faulty ICBM or shorter range missile. There is still time to contain this threat, even after tonight’s test, but some hard choices lie ahead for Japan and the US. Odds are that Japan will make the most of that time. We should too.

So far, all we’re doing is talking sanctions at the UN. Sanctions don’t work and certainly won’t change Kim Jong-Il’s behavior. North Korea is already the world’s most isolated state, and economic punishment may increase the likelihood of its selling weapons to terrorists to obtain hard currency. Kim Jong-Il will have to be either scared straight or taken out. A weak response to him now will embolden him and signal to the Iranians that we won’t stop them, either.

More: As John at Op-For says, “Our missiles work. Theirs don’t.” So far.

We have a window of time, of unity with Japan (which possesses a successful space program that can be turned into a missile program in short order) and South Korea and possibly China and Russia, to deal with the North Korean threat. It’s not too late yet, but it will be too late too soon.