Jung Yeon-Je/AFP/Getty Images
A protester burns a mock North Korean nuclear missile during an anti-North Korea rally in Seoul on Tuesday.
North Korea's nuclear weapons program has been of great concern to major powers in the region, especially China, South Korea, Japan and the United States, which have spearheaded negotiations aimed at ending that program.
But North Korea has suspended its participation in those talks and now has reportedly conducted a nuclear weapons test.
Here are the implications of that test for these key countries and their differing approaches to the ongoing problem.
No country has more leverage over North Korea than China does. Both countries are ruled by communist parties. China sends desperately needed food and energy assistance to North Korea.
Yet even China was unable to dissuade Pyongyang from conducting its reported nuclear weapon test this week. In July, China also was unable to prevent North Korea from test-firing a long-range ballistic missile, which blew up some 40 seconds after launch. A few days later, Pyongyang rebuffed China's call for a resumption of nuclear disarmament talks.
China could impose great economic and military pressure on North Korea but is unwilling to do so, fearing a precipitous collapse of the North Korean regime. This collapse could lead to even more insecurity on the peninsula and waves of refugees pouring across the border into China. It also could draw the South Korean military and its U.S. allies into North Korea — at China's doorstep.
As a result, China opposes calls for stringent international sanctions and military action against the North. China's U.N. Ambassador Wang Guangya put it this way: "I think there has to be some punitive actions, but also I think these actions have to be appropriate." He said the U.N. Security Council must give a "firm, constructive but prudent response." China's foreign ministry spokesman, Liu Jianchao, says military action is "unimaginable."
As one of the five permanent members of the Security Council, China can use its veto to prevent robust Council action against North Korea.
South Korea shares China's concerns about a possible collapse of the North Korean government. In addition to the likely surge of refugees, the economic costs of stabilizing and perhaps reuniting with the North would be staggering. The burden that West Germany incurred by unifying with East Germany pales in comparison to the probable cost of reunifying North and South Korea because of the extreme disparity in wealth between the two.
South Korea also opposes military action against the North. A military conflagration would be devastating to South Korea. Sometimes overlooked in the debate about North Korea's nuclear weapons is its large conventional force. Analysts doubt that the North could sustain a prolonged military campaign, but it could do tremendous damage to Seoul — which is within artillery range of the demilitarized zone, or DMZ — in a very short time.
In recent years, South Korea has pursued a "sunshine policy" of engagement with the North, promoting trade, tourism and dialogue across the DMZ. South Korean President Roh Moo-hyun says that policy will be reviewed.
North Korea's long-range missile test fizzled in July. But in 1998, Pyongyang tested a similar long-range missile and sent part of it right over Japan. The incident underscored Japan's vulnerability to attack, and intensified a debate about amending the country's pacifist, post-World War II constitution.
North Korea's reported nuclear weapons test this month will further intensify that debate and perhaps give a boost to Japan's new prime minister, Shinzo Abe. He wants to amend the constitution, adopt a more assertive foreign policy and strengthen military cooperation with Japan's strongest ally, the United States.
North Korea's nuclear ambitions have a special resonance in Japan, the only country to have suffered nuclear attack. But Prime Minister Abe has said he will not seek nuclear weapons as a deterrent to North Korea. After the reported nuclear weapons test, Abe told lawmakers: "There will be no change in our non-nuclear arms principles."
In contrast to his policy in Iraq, President George Bush in recent years has emphasized the importance of multinational diplomacy in dealing with North Korea.
Though the United States would never forswear the military option, it continues to emphasize diplomacy as it seeks a U.N. Security Council resolution tightening sanctions on the North. Aware of the desperate poverty of the North Korean population, the United States wants to target sanctions against the elite in Pyongyang and against the military.
Washington's primary concern is that North Korea might try to sell nuclear weapons technology to other countries, or even terrorist organizations. Weapons sales have been an important source of revenue for the North in the past.
With that threat in mind, President Bush issued a warning to North Korea on the day of the reported nuclear test: "The transfer of nuclear weapons or material by North Korea to states or non-state entities would be considered a grave threat to the United States and we would hold North Korea fully accountable for the consequences of such action." The United States is seeking international support for efforts to intercept any weapons transfers from North Korea to other entities.