The U.S. government says North Korean plans to conduct a nuclear weapons test are a "provocative action" and an "unacceptable threat to peace and stability." As opposed to the U.S. threats to conduct nuclear weapons tests by dropping them on the heads of Iranians and others, which no doubt are a contributor to peace and stability and completely nonprovactive. Or as opposed to the new Japanese Prime Minister Shinzo Abe, who recently suggested that "Tokyo should study whether its constitution would allow a pre-emptive strike on North Korean missile bases." Another unprovoked action designed to promote peace and stability, no doubt.
We're told by the Washington Post reporters that Japan "sees itself as a primary target of North Korean aggression." The Post seems to have left out the word "hypothetical," since there hasn't been any such thing as "North Korean aggression" for more than 50 years (and even that was quite arguably a response to an imminent invasion of its territory, an invasion certainly a lot more imminent and a lot more likely than the "imminent" threat to the U.S. from non-existent Iraqi WMD which has caused the deaths of hundreds of thousands of people). If the Japanese are worried about aggression threatening their lives, I'd suggest they'd do better to worry about the aggression being committed around the world by their number one ally.
As for North Korea, the fact that their development of nuclear weapons is for defensive purposes against a very real threat to their nation is so obvious as to be almost not worth noting, except in the face of the topsy-turvy world of Western corporate media.