Washington – U.S. spy agencies on Monday confirmed North Korea’s nuclear test, even as Secretary of State Condoleezza Rice declared that U.N. sanctions prove the world is united in opposing Pyongyang’s nuclear ambitions.
Such strong opposition should be a warning to Iran, too, said Rice, who is leaving this morning for an Asian trip that is expected to be dominated by the nuclear issue. She will visit Japan, South Korea, China and Russia.
Providing the government’s first definitive confirmation that North Korea had detonated a nuclear device a week earlier, National Intelligence Director John Negroponte’s office said in a statement Monday that air samples collected Wednesday showed evidence of radioactivity. That verified North Korea’s claims.
“The explosion yield was less than a kiloton,” the statement said, smaller than many experts had expected.
A kiloton is equal to the force produced by 1,000 tons of TNT.
An intelligence official said the North Korean device was believed to be roughly the equivalent of 200 tons of TNT, suggesting to analysts that it was probably a partial failure. Experts in and out of government had anticipated a detonation of at least several thousand tons. The official spoke on condition of anonymity because of the sensitive situation with Pyong yang.
Nuclear experts said the fact the bomb was made with plutonium was important because it suggested that North Korea has only one nuclear program mature enough to produce weapons.
They strongly suggested that the country’s second, secret path to a bomb – based on uranium and provided to North Korea by Pakistan’s former nuclear head – is not yet ready.
“This is good news because we have a reasonably good idea of how much plutonium they have made,” said Siegfried S. Hecker, the former head of the Los Alamos National Laboratory and now a visiting professor at Stanford University.
Hecker, who has visited North Korea and seen parts of the country’s nuclear infrastructure, said that it was his guess that “they tried to test a reasonably sophisticated device, and they had trouble imploding it properly.”
The supply of plutonium materials is known from the days when international inspectors kept tabs on the fuel rods in the North’s reactor, and intelligence analysts estimate North Korea has enough material to make six to 10 bombs.
At the State Department, Rice said the world “has responded calmly and firmly” to the test.
“North Korea cannot endanger the world and then expect other nations to conduct business as usual in arms or missile parts,” Rice said, previewing her message for the Asia trip. “It cannot destabilize the international system and then expect to exploit elaborate financial networks built for peaceful commerce.”
She said Iran – another government accused of running an illicit nuclear program – should pay attention to the global reaction. That would include the U.N. Security Council’s sanctions adopted Saturday, aimed at making life difficult for the North Korean government and its weapons proliferation business.
“The Iranian government is watching, and it can now see that the international community will respond to threats from nuclear proliferation,” said Rice, who added that she believes the Security Council will begin working on a sanctions resolution against Iran this week.
No military action
The U.S.-sponsored U.N. resolution acceded to Russian and Chinese demands that military action be ruled out.
The United States, North Korea and seven other nations are now believed to have nuclear arms. Yet North Korea’s unpredictable behavior and its history of trading weapons and components make its nuclear advancements particularly worrisome to its neighbors and the international community.
The U.S.-sponsored United Nations resolution on North Korea demands that Pyong yang eliminate nuclear weapons. But it also rules out military action against the country, as the Russians and Chinese demanded.
It calls on countries to block North Korea from receiving equipment or materials to build weapons of mass destruction and other advanced weaponry. It also would clamp down on travel for North Koreans involved in the weapons program and freeze many of the international assets of people or businesses connected to that program.
After the resolution was unanimously passed, North Korea’s U.N. ambassador accused council members of a “gangsterlike” action that neglects the nuclear threat posed by the United States.
Rice acknowledged international concerns of escalating the crisis and said she would address that on her trip. Countries in the region worry that the collapse of North Korea’s government could send millions of refugees streaming toward their borders.
South Koreans also worry about a conventional attack by their neighbor.
“We have no desire to ratchet up conflict,” Rice said. “But we’ll have some discussions on precisely how this will be carried out.”
While China has been inspecting cargo trucks headed for its communist ally, its U.N. ambassador indicated its inspectors will not board ships to search for suspicious equipment or material, raising questions about how strictly it and South Korea will enforce the U.N. resolution. Both countries have significant trade relations with North Korea, whose economy is perpetually on the verge of collapse.
The New York Times contributed to this report.
