By Senior National Security Producer Suzanne Kelly
The U.S. and North Korean delegations left Geneva last week with no firm plan for re-starting talks aimed at ending Pyongyang's nuclear program - perhaps not surprising, but concerning, given that nuclear experts estimate that North Korea has enough plutonium to arm about a dozen weapons.
Even more concerning is recent evidence of just how quickly North Korea's nuclear program is being developed.
Professor Siegfried Hecker, who helps lead the Center for International Security and Cooperation at Stanford University, and advises the U.S. government, is one of the few who have seen the evidence that the North Korean program has progressed enormously since the last official talks ended in 2002.
On a trip to North Korea last November, he saw two things that concerned him. The first was an experimental light-water reactor (LWR) that appeared to be in the early stages of construction, suggesting that North Korea had mastered the technology to make a LWR on its own.
The LWR could be used to help drive a civilian nuclear power program, but could also be easily adapted to manufacture the material needed for a nuclear bomb. But even that discovery paled in comparison to what else he saw.
Hecker was led by his North Korean handlers into a facility that he described as "ultra-modern" and "clean." There, before him, were some 2,000 large cylinders lined up as far as he could see.
"It was far beyond my expectations," said Hecker, who has visited the country as an invited expert more than half a dozen times.
Hecker found himself standing on the edge of North Korea's uranium centrifuge facility. This was the confirmation he needed to conclude that North Korea, indeed, was pursuing a second path to the bomb.
The existence of the uranium centrifuge facility meant that the North Koreans were now able to enrich uranium by using a centrifuge to concentrate it, Hecker explained. The result is highly-enriched uranium, or HEU, the material needed to make a nuclear bomb that could kill thousands and contaminate swaths of land and sea.
The last time anyone had talked with the North Koreans formally, they had denied having a uranium program.
The centrifuges appeared to Hecker as if they may be second-generation, which would indicate that the North Koreans had made far more progress than anyone had expected since the last formal talks to end the country's nuclear program came to an abrupt halt.
"Just the sight of that many centrifuges and that modern of a facility was just mind-boggling," said Hecker.
The world knew that the North Koreans had a plutonium complex at Yongbyon. Hecker and many other experts had seen it.
But the North Koreans had agreed to freeze that facility and not operate it. It was a deal Pyongyang struck with the U.S. in exchange for light-water reactors, which could be used to help generate nuclear electricity.
Now that the North Koreans have their own technology, it could change the landscape once again.
"I'm considerably more concerned that they would expand their program," said Hecker. "Because they've also demonstrated their capacity to take the second route to the bomb, that complicates things enormously."
For Paul Brennan, a senior analyst at the Institute for Science and International Security (ISIS), the discovery of the uranium centrifuge facility was a confirmation of his worst suspicions.
"Their program was based on plutonium,and that had been the focus for many years," said Brennan. "There had always been suspicions about a uranium enrichment program and under the Bush administration, they accused North Korea of having an active nuclear enrichment program for nuclear weapons."
Both plutonium and uranium can be used in the development of nuclear weapons.
International experts now have an extremely limited ability to monitor North Korea's uranium enrichment and the possibility that Pyongyang would have the ability to export enriched uranium is a red flag for security officials, because the signature for HEU detection is very small.
"The concern with the uranium enrichment program, is that it is tied to nuclear weapons. As time goes by, it gives North Korea greater capabilities. Any nuclear program that is allowed to continue and develop, is going to increase their capability," said Brennan.
"And so if they indeed have made HEU, which they at least now have the capacity to do, then the biggest concern I have is that they either export those technologies somewhere else, or that they would export HEU," said Hecker.
It's a concern shared by Robert Gallucci, president of the John D. and Catherine T. MacArthur Foundation, who worries that North Korea may sell material, be it plutonium or HEU, or would sell the capability and technology to build a rector, or even sell a nuclear weapon.
"Let's remember that the North Korean's built a plutonium production reactor for Syria. They built a reactor designed specifically to produce plutonium for nuclear weapons. This was a reactor with a purpose for producing plutonium for nuclear weapons. That would be operating right now had the Israelis not flattened it," said Gallucci.
"You can't exclude any of these suggestions as fantasy. This is something to worry about. This is the thing I would worry about most from a U.S. national security perspective."