It's little wonder that South Koreans are thinking about ways to defend themselves, given North Korea's bizarre and dangerous behavior. The North has recently launched a long-range rocket and conducted its third nuclear test. It has also unleashed a barrage of apocalyptic threats, including potentially launching "pre-emptive nuclear strikes" on Seoul and the United States and declaring the 1953 Korean War armistice nullified.

In response, some influential South Koreans have urged that the South develop its own nuclear arsenal, and recent polls show that two-thirds of the population concurs. The government is pushing the United States to let it reprocess spent nuclear fuel under a new nuclear cooperation agreement. Such capability could make it easier to develop nuclear weapons, if Seoul ever decided to do so.

Needless to say, these are terrible ideas that will not make South Korea safer. The United States and Russia, which possess the overwhelming majority of the world's nuclear weapons, have significantly reduced their numbers, and there is talk of further reductions.

In recent years, the international community has demonstrated rare unity in imposing sanctions on Iran and North Korea to curb their nuclear ambitions. Those efforts will be made even harder if South Korea, which gave up plans for a nuclear weapons program in the 1970s, moves forward on nuclear weapons now.

Besides, the United States — the South's longtime treaty ally with 28,500 troops based there — will come to its defense if needed. Tom Donilon, the national security adviser, reinforced the point last week when he said America would "draw upon the full range of our capabilities to protect against, and respond to, the threat posed to us and to our allies by North Korea."

South Korea would do better spending the billions of dollars that nuclear weapons would cost on conventional capabilities that would actually enhance its security. The United States recently bolstered the deployment of ballistic missile defense warships in waters off the Korean Peninsula and on Friday, Defense Secretary Chuck Hagel announced that the Pentagon is enhancing America's ability to defend itself from a North Korean nuclear missile attack by deploying up to 14 additional ground-based interceptors on the West Coast.

Many experts say that the North's new leader, Kim Jong Un, is looking to enhance his political position, not start a war. But there is a growing risk of miscalculation. There is also every reason to believe that adding the threat of nuclear weapons from the South would inflame the situation, not calm it.