PARIS — When North Korea announced its nuclear test last week, it was just the latest sign that the effort to contain the spread of atomic weapons was breaking down: Several countries are on the verge of beginning uranium enrichment programs, and others have already started such efforts, policymakers and experts say.
Brazil recently inaugurated an industrial-scale uranium enrichment plant, and Argentina and South Africa are interested in similar projects. Australia, which has large supplies of natural uranium, is also considering an enrichment program. Iran has defied requests by the international community to suspend its program to enrich uranium, the first step toward making the fissile material suitable for a bomb.
North Korea's announcement of a test follows ones by India and Pakistan in 1998. The rise of a new generation of nuclear states has led to increasing concerns that others could follow, and fueled fears that the more countries with nuclear capability, the greater the risk that fissile material will fall into terrorist hands.
"We are, at present, at the unraveling of the nonproliferation regime and the global nuclear order that we've taken for granted," said Graham Allison, a former assistant secretary of Defense under President Clinton, who directs the Belfer Center for Science and International Affairs at Harvard University. "This is a huge event whose importance may only become evident in five years....
"In terms of global order, global nuclear order, this is a nuclear blast," he said.
On Saturday, the United Nations Security Council unanimously adopted a resolution imposing sanctions on North Korea for its declared nuclear test Monday.
But China's reluctance to take part in inspections of North Korean cargo to help stop the flow of weapons materials throws into doubt how effective the sanctions can be.
Policymakers point to three levels of problems with the Nuclear Nonproliferation Treaty, which has been in force for 36 years: weaknesses in the treaty itself, at the political level in the Security Council, and at the technical level in the ability of nuclear inspectors to detect undisclosed nuclear programs.
Countries that had nuclear weapons when the treaty went into effect -- the United States, Russia, Britain, France and China -- were allowed to keep them, whereas others were asked to forswear them.
