Fears grow of wider spread of nuclear weapons

Reports of nuclear experiments in South Korea and an unexplained blast in North Korea are stoking fears that other countries may increasingly feel compelled to move toward a "nuclear tipping point".

Few officials and experts predict non-nuclear states will make a mad dash to acquire outright the capability now possessed by the five declared nuclear powers - the United States, France, Britain, China and Russia - and three undeclared powers - Israel, India and Pakistan.

But they are concerned that some governments - warily watching nuclear activity in the two Koreas and Iran - may begin to reconsider their own status and start amassing the materials and technologies needed to leap quickly into the nuclear club in the future.

"If the assumption becomes widespread that everybody's doing it, that everyone is experimenting in these areas, then this will tend to erode a taboo against illicit nuclear activities," Robert Einhorn, the top non-proliferation official under former President Bill Clinton, said.

Mr Einhorn, co-editor of a new book called The Nuclear Tipping Point, said it is important that questions about programmes carried out by the two Koreas and Iran "be resolved in such a way as to rebuild support for staying away from these sensitive technologies".

North Korea's nuclear programmes have been a source of US alarm since the early 1990s, while Iran came into focus more recently. Tehran denies Washington's charge of pursuing an aggressive nuclear weapons programme.

But South Korea, a key US ally, was believed to have abandoned any nuclear weapons-related pursuits under pressure from Washington in the 1970s.

And while Pyongyang is estimated to have produced one or two weapons and maybe enough nuclear fuel for a half dozen more, an actual nuclear test would add a more ominous dynamic to the region's security situation.

A huge explosion rocked North Korea three days ago. US and South Korean officials said yesterday it was unlikely to have been a nuclear weapons test despite a report the blast produced a mushroom cloud. But the New York Times reported yesterday the Bush administration had received recent intelligence reports that some experts believed could indicate North Korea was preparing to conduct its first nuclear weapons test explosion.

Both Korean developments could complicate the search for a diplomatic solution to Pyongyang's nuclear ambitions as America goes about choosing its next president.

Nuclear expert Joseph Cirincione, interviewed before the North Korea incident, said last week's revelations about South Korea's previously secret 1982 and 2000 tests "makes everybody a little more nervous than they were two weeks ago".

Seoul insisted the experiments were over and it did not have a weapons programmes.

But Mr Cirincione, who heads the Carnegie Endowment for International Peace's non-proliferation project, said that now:

"Other countries may begin to hedge their bets a little bit to just explore their options (and this would) move them all a little closer toward the nuclear weapons option."

Mr Einhorn's book, co-edited with Mitchell Reiss, the State Department policy planning director, and Kurt Campbell, a former senior Pentagon official under Clinton, examined how and why countries might reconsider decisions to forgo nuclear weapons.

"In ways both fast and slow, we may very soon be approaching a nuclear 'tipping point' where many countries may decide to acquire nuclear arsenals on short notice, thereby triggering a proliferation epidemic," Reiss wrote in the book's lead chapter.

The authors concluded that the perceived reliability of US security assurances would be a critical factor in whether countries like Japan, Saudi Arabia, South Korea, Taiwan and Turkey go nuclear.

If they did choose to pursue it, it would take three to five years, maybe more, for Saudi Arabia, Egypt, Syria, Turkey and Japan to acquire indigenous nuclear capability, the book said.

As for South Korea, the book argued that despite an impressive engineering base and technological infrastructure, it would take years of effort for Seoul to develop a nuclear weapon.