The Japanese parliament’s passage of a controversial bill that might be interpreted as opening the way for Japan to produce nuclear weapons is a move of no help for regional peace and security. Above all, it could be used by North Korea to justify its nuclear program.

But last week’s revision of Japan’s atomic energy law, which adds a phrase that the use of nuclear power should contribute to guaranteeing national security, appears to have no realistic likelihood of leading to its nuclear armament.

To go nuclear, Tokyo would have to risk being alienated in the international community and endangering its alliance with the U.S. The attempt would also hit the wall of the Japanese public’s overwhelming antinuclear sentiment.

The Japanese government tried to calm the suspicion, with Chief Cabinet Secretary Osamu Fujimura making it clear Tokyo has no intent of putting nuclear power to military use, and there would be no change to its principles of not manufacturing, possessing or allowing the entry of atomic weapons.

Japanese lawmakers who engineered the passage of the bill apparently had the ulterior motive of at least partly unlocking the restriction on Japan’s military nuclear capability. It is hard to buy their argument that the amendment was aimed at strengthening safeguards in time for the establishment of an independent regulatory body responsible for the nuclear sector.

If they really consider the concerns as resulting from misunderstanding, it could not be difficult to delete the controversial phrase, but we believe that will never happen.

What is more worrisome is that the revision comes in line with a series of measures aimed at putting Japan on a road toward a strengthened military posture.

Right-leaning Japanese parties are likely to step up efforts to revise the pacifist constitution that bans the use of military power as a means of settling international disputes.

Behind Japan’s military buildup is apparently its growing concern over threats from North Korea, and China’s rise as another superpower rivaling the U.S.

A South Korean security official reportedly said last week that China might have to be held responsible for Japan’s anxiety as it has left Pyongyang’s nuclear ambitions unchecked.

This view, however, seems narrow-sighted, as Japan’s moves appear fundamentally motivated by China’s growing power. Japan’s military buildup, in turn, is likely to prompt China to take corresponding measures, further heightening tensions in Northeast Asia.

In this context, Japan’s latest nuclear step might be an occasion for Seoul officials to reflect on the ongoing attempt by the U.S. and Japan to contain the expansion of China’s power.

A day after Japan’s Diet passed the bill, South Korea joined the U.S. and Japan in a trilateral naval drill in the East China Sea.

The Lee Myung-bak administration has moved to strengthen military cooperation with the U.S. and Japan, with apparent encouragement from Washington.

But as shown in the controversy over the revision of Japan’s nuclear law, there is certainly a limit on Seoul’s acceptance of Japan’s military posture.

Though the U.S. alliance should no doubt be the backbone of South Korea’s security, a question might still be raised over the wisdom of synchronizing with the strategy of the U.S. and Japan to keep China’s growing influence in check.

Some critics here say South Korea was too eager to follow the U.S. initiative during recent talks between foreign and defense ministers from the two sides in Washington.

The situation surrounding the Korean Peninsula is not simple enough to allow Seoul to bind itself to strengthening a trilateral military alliance with the U.S. and Japan, while discomforting China.

It is time for Seoul strategists to be far-sighted enough to reach a strategic balance rather than simply drifting back into Cold War confrontation.