Tensions on the Korean Peninsula remain high following North Korea's latest nuclear weapons test and the firing of six short range missiles. The United Nations Security Council is considering new sanctions against Pyongyang, amid increasing concerns about the potential for nuclear proliferation and the stability of the North Korean government.

U.S. President Barack Obama, facing the first direct challenge to his administration by an emerging nuclear weapons state, says America and its allies will "stand up" to the North Korean government. "North Korea's nuclear and ballistic missile programs pose a grave threat to the peace and security of the world and I strongly condemn their reckless action," he said.

America's top military officer, Admiral Mike Mullen, the Chairman of the Joint Chiefs of Staff, says he sees a growing belligerence on the part of North Korea and a rising defiance of international law. "All of those things point to a country that I think continues to destabilize that region and actually in the long term, should they continue on to develop a nuclear weapons program, pose a significant threat to the United States," he said.

The United States and numerous other countries reacted with outrage at North Korea's latest nuclear test and missile launches, which have drawn widespread condemnation.

Analysts like Richard Bush, the director of the Northeast Asia Policy Center, say North Korea is a weak power, which makes the country's nuclear program critically important to the government in Pyongyang. "North Korea appears to believe that it is seriously threatened by the United States. It believes that it needs an effective deterrent against that. In fact nuclear weapons are the poor country's ideal deterrent," he said.

South Korean and U.S. troops have raised their alert level on the Korean Peninsula, after Pyongyang threatened to abandon the 1953 armistice that ended the fighting in the Korean War.

The combined forces command has not raised its alert to the higher level since North Korea conducted its first nuclear explosion in 2006.

Michael O'Hanlon, a senior fellow in foreign policy at the Brookings Institution, says despite North Korea's nuclear test, it is unlikely the country's military has the means to attack its neighbors with atomic weapons anytime soon.

"Putting a nuclear weapon on a missile, making it small enough to be carried by the missile, allowing it to survive atmospheric reentry, even on a medium range rocket, is no trivial matter. There is a very decent chance that either the thing would fail or we would be able to shoot it down with theatre missile defense," he said.

The North Korean threat to discard the armistice followed Seoul's decision to join a U.S.-led anti-proliferation initiative involving intercepting ships suspected to be transporting weapons of mass destruction and related materials.

O'Hanlon says the greatest danger from North Korea is that it might sell its nuclear technology to other countries or terrorist groups. "The most worrisome thing is the sale of nuclear material because if they attack South Korea their regime will end. I cannot believe they really doubt that. So the only thing they can really plausibly get away with is the sale and that is why I worry about it most," he said.

Analysts say North Korea has, in the past, provided weapons technology to other countries such as Iran and Syria.

Carlos Pascual, the director of foreign policy at the Brookings Institution, says such proliferation drastically increases the danger missiles and weapons could be used in actual combat. "If in fact we start seeing a world where nuclear weapons are being used as tactical weapons in regional theatres, then the risk of the use of those weapons increases astronomically in comparison to what the risk of the use of those weapons was when it was a world of mutually assured destruction between the United States and the Soviet Union," he said.

North Korea's nuclear test came against the backdrop of uncertainty about the country's reclusive leader, Kim Jong Il, and who might succeed him.


Mr. Kim suffered a stroke last year, which analysts say prompted him to prepare a transfer of power to his youngest son, Kim Jong-un, who is believed to be about 26 years old.

Dennis Wilder, a former senior director for East Asian Affairs on the National Security Council, says once plans for a smooth transition are in place, North Korea may be willing to reopen negotiations about its weapons program. "I am not saying they will, but if we believe that the succession issues are driving a lot of this behavior at this moment, once Kim thinks he has his youngest son in position he may then be willing to deal with the outside world again," he said.

Members of the U.N. Security Council are considering new sanctions against North Korea. These could include expanding an arms embargo and financial restrictions.