Yet another nation has gate-crashed the 'exclusive' nuclear club. North Korea's nuclear test will impinge on important bilateral relationships in Northeast Asia and affect popular perceptions of foreign and security policy in Japan and South Korea.

China had backed a strongly worded UNSC resolution against North Korea following the latter's missile tests in July; it did not mince words with its Foreign Ministry stating North Korea had "flagrantly" tested in "disregard" of the "common opposition of the international community." For the Chinese, this represents an abject diplomatic failure; it leaves them without face and without the means to force tougher action against it small neighbor without international support. It was circumspect for China to promote the six-party talks under the guise of multilateralism, aware that no action could be taken without its agreement. Effective UN action in its backyard could be difficult to accept but, if the Chinese were to use their veto to block such action, it would prove that if Kim Jong Il had assumed that Beijing would eventually cover him, he was right. The strong emphasis in the Chinese statement on a calm response and on "seeking a peaceful solution through consultation and dialogue," suggests this is what might happen. But, if the Chinese decide that enough is enough, then crowning Shinzo Abe's visit to Beijing, this would lead to a thaw in the Sino-Japanese relationship. In the interests of keeping the Americans from getting involved China might join Japan and South Korea to formulate a regional response to the crisis.

If the Japanese take up this offer, they can gain their normalization without upsetting China and South Korea, and without the US having to push it. This remains an unlikely scenario, and Abe might only succeed in working more closely with the US and, to a limited extent with the South Koreans. North Korea's nuclear test, however, proves Abe right in his uncompromising stand towards that country. It is unlikely that Japan will use this excuse to go nuclear, but it does give Abe an opportunity to fast forward his constitution-revision plans and find a more receptive public for it. Hopefully, he will not need history and shrine visits any more, if his only aim is to achieve 'normality' for Japan - the North Korean nuclear test is sufficient.

It is South Korea that has the most to lose from the nuclear test. Embattled President Roh Moo-hyun, will come in for criticism regarding his "groundless illusions" (ChosunIlbo, 4 October) thesis about North Korea which has led to increasing pressure on South Korea's military alliance with the US. Under attack domestically for his plans to regain wartime control over the South Korean army from the US, the cost of the North's nuclear test could be either Roh's exit, or increased pressure on the alliance.

Both South Korea's soft approach and the US's hard line on North Korea were misguided. Bush did the US no favor when, despite the Agreed Framework of 1994, he branded North Korea as part of the "axis of evil" in his first term. Then, at the six-party talks in September 2005, despite implying that North Korea might get light-water reactors, he killed the deal by imposing too many conditions. This standoff has now created an eighth nuclear power. The White House, while quick to call on the UN Security Council "to take immediate actions to respond to this unprovoked act," is considering plans for unilateral interdiction of ships going to and leaving North Korea. The Bush administration should, however, ponder over its role in the events leading to the current situation, and whether a solution could not have been found over the last five years. As The Washington Post puts it, the North Korean action is "a failure of the Bush administration's nuclear nonproliferation policy."

In the light of this "failure," India might be nervous, with good reason, about the future of the Indo-US nuclear deal. All its fulminations about Pakistani links with the North Korean nuclear and missile programs cannot reduce the new threat to the deal on Capitol Hill - the Senate still has to approve the deal. For Beijing, this might be a welcome fallout of the North Korean test, though its policy approaches towards the Iranian nuclear issue might now be constrained. For the US, how it responds to the current crisis will have implications on how Iran plays its cards. In addition, the true danger from the North Korean action is not from Kim Jong Il using his nuclear weapons as from his sharing what he has with other states and non-state actors.