North Korea's claimed test of a nuclear device has raised fears that North Korea's non-nuclear neighbors will be compelled to develop their own such weapons. But such a scenario is considered unlikely.
While Monday's explosion in North Korea apparently generated a small seismic wave detected around the region, the geo-political tremor could be enormous.
Japanese Foreign Ministry spokesman Tomohiko Taniguchi acknowledges that there is some sentiment in Japan for the country to develop its own nuclear weapons.
"There is a number of politicians, political pundits, opinion holders in Japan that are saying that if indeed North Korea goes nuclear, Japan has to think about its own future strategy," said Taniguchi.
Such speculation was long taboo in Japan, the only nation to undergo a nuclear bombing. But North Korea's one-day barrage of missile test launches last July brought to the surface what was once spoken mainly in private.
Pyongyang's announcement Monday that it had exploded a nuclear device is likely to make such talk more common.
The United States, Japan, South Korea and China quickly condemned the North's action, saying it threatened regional security.
Yoshinori Suematsu, a member of parliament from the opposition Democratic Party, is one of Japan's leading non-proliferation advocates. He says he fears that the mood in Japan will now start to shift toward acquiring nuclear weapons.
"In the past there is no such argument that Japan should have nuclear arms," he said. "So a nuclear test by North Korea will accelerate such kind of mood."
But the Foreign Ministry's Taniguchi, reflecting the opinion of many others, says a nuclear Japan is unlikely. He says accelerated cooperation on conventional weaponry between Japan and the United States has been in the works for a long time. Taniguchi says that while Japan might play a larger regional role, this does not mean it will attempt to become a nuclear power.
"The security ties between Tokyo and Washington, D.C. have never deteriorated - to the contrary, have improved," said Taniguchi. "Japan is willingly going to shoulder some of the burdens of providing security to the region with the United States - but in a traditional fashion, of course."
Japan, South Korea and Taiwan all have advanced civilian nuclear power technology, which would give them a head start if they decided to make nuclear weapons. All three, however, would face tremendous opposition from both Washington and Beijing if they moved in such a direction.
All three have been covered by the so-called U.S. nuclear umbrella. This has acted for decades to prevent instability in the region.
South Korea and Taiwan have considered the nuclear option in the past. Seoul bowed to pressure from Washington in the 1970's and '80's to terminate its secret nuclear weapons programs, however, and has pledged that it will not acquire such weapons. Taiwan aborted a covert program to develop a nuclear weapon that ran for decades.
While the world awaits the regional effect of Monday's North Korean explosion, it is no clearer what the effect will be on North Korea itself.
Some analysts believe that North Korean leader Kim Jong Il and his military expect a nuclear test to lead the world to accord Pyongyang a new level of respect.
But the immediate reaction, at least, appears more likely to be further isolation of the country, and stronger sanctions by the West, Japan and South Korea. Even Pyongyang's long-time friends in Moscow and Beijing are expected to move away from the regime. Shortly after Monday's explosion was announced, China's Foreign Ministry said Beijing "resolutely opposes" any North Korean nuclear test, and hopes Pyongyang will return to disarmament talks.
Management consultant T.W. Kang of Global Synergy Associates in Japan has visited North Korea on business. He is concerned that Kim Jong Il's nuclear strategy could backfire, causing regional instability.
"If he goes ahead and does this and he can't get the effect out of this, there may be some kind of strife in the [North Korean] military, within his party. All sorts of things are possible," said Kang. "If there was any argument behind diplomatic avenues to solving this problem, it was probably the fact that we want to keep that regime in some semblance of stability."
Before North Korea's missile tests and threats of a nuclear test, China and South Korea - and to a lesser extent, Japan - had taken a cautious approach to Pyongyang. Kang says they fear the economic and social consequences of a sudden collapse of the Stalinist state, with its 23 million impoverished people.
"I'm sure that the Chinese would not appreciate that. I'm sure that the Japanese would have a hard time dealing with boat people floating across the Sea of Japan," added Kang. "The South Koreans would have a hard time."
Analysts calculate that such a collapse could cost the region hundreds of billions of dollars, with South Korea bearing a major part of the cost, but with China, Japan and the United States all being forced to play major roles in restoring order in North Korea.