North Korea's latest nuclear test — whether or not it was a successful hydrogen bomb blast that the reclusive state claims it was — deserves strong condemnation as a grave threat to regional security and nonproliferation efforts that flies in the face of international sanctions. It comes as no surprise that government officials have indicated they would consider stepping up Japan's sanctions — which were partially lifted two years ago as Pyongyang promised a fresh probe into the fate of Japanese abducted by North Korea in the 1970s and '80s.
The underground nuclear test, the fourth since 2006 and the second since Kim Jong Un became the country's supreme leader in 2012, will make any progress on the abduction issue — the resolution of which the administration of Prime Minister Shinzo Abe has given high priority — even more difficult, although the process was already viewed as effectively stalled.
It is widely believed that the Kim regime — which has been consolidating its power through a series of purges — has embarked on the latest test in defiance of international sanctions against its nuclear weapons and missile programs to ratchet up regional tensions and corner the United States into resuming long-suspended dialogue. Japan needs to keep in step with other countries involved to let Pyongyang know its gamble won't be rewarded.