NKorean nuclear test may be intelligence windfall

TOKYO (AP) — North Korea's latest underground test shows it is making big strides toward becoming a true nuclear power. But the test may also reveal key clues the secretive nation might have hoped to hide about how close, or how far away, it is from fielding anuclear weapon capable of striking the United States or its allies.

Hoping to capitalize on a rare opportunity to gauge North Korea's nuclear capabilities, intelligence and military officials around the region are scrambling to glean data to answer three big questions: how powerful was the device Pyongyang tested, what sort of device was it, and what progress does the test indicate the nation has made.

North Korea hailed Tuesday's test as a "perfect" success, saying it used a device that was stronger and more advanced than those in its past two attempts. Add that to its successful rocket launch in December and the threat of a North Korea ready to strike at the United States, which it sees as its arch-enemy, would appear to be more real than ever.

But just how close is it?

The main thing intelligence officials want to figure out is what kind of device was used. Was it a plutonium bomb, like the ones it tested in 2006 and 2009, or one that used highly enriched uranium?

James Acton, an analyst with the Carnegie Endowment for International Peace, said North Korea's plutonium stockpile is small and it would be difficult and expensive for the North to produce more. But a test using highly enriched uranium, which is cheaper and easier to produce, would raise the threat that North Korea can expand its nuclear arsenal quickly.

"A highly enriched uranium test would be a significant development," he said. "Unfortunately, we don't yet have any evidence as to the device's design yield or whether it was made from plutonium or highly enriched uranium."

Finding that out is a race against time.

Joseph De Trani, former head of the National Counterproliferation Center, predicted U.S. intelligence would determine the size and composition of the nuclear device in one to three days based partly on radioactive elements released into the environment.

"Highly enriched uranium is something that degrades quickly, so you would have to collect within a 24-hour period," especially because the traces from an underground explosion will be minimal, he said.

Neighboring Japan may provide some of those answers.

Its fighter jets were dispatched immediately after the test to collect atmospheric samples. Japan has also established land-based monitoring posts, including one on its northwest coast, to collect similar data.

But experts caution such monitoring doesn't always work because test sites can be sealed to prevent tell-tale leaks. They also note that North Korea has proven it has the ability to mask its tests quite well. No radioactivity was detected after North Korea's test in 2009.

The first indication of the latest test was seismic activity at the test site, which U.S. officials estimated at roughly magnitude 5.1. That would be equivalent to a medium-sized earthquake. North Korea's two previous tests registered at magnitude 4.3 and 4.7.

Working off that data, South Korean officials estimate the yield of the device — a measure of how strong its explosion is in comparison to TNT — to be between 6 and 7 kilotons. The United States has estimated it at "several kilotons." Either way, it would be North Korea's biggest yield yet but far less than that of the weapon dropped on Hiroshima in 1945, which was about 20 kilotons.

"Because the depth of the test is not known and the geology of the test site is uncertain, translating the seismic magnitude into yield is difficult," said Acton, the Carnegie analyst. "My own back-of-the-envelope calculation suggests a yield of between 4 and 15 kilotons."

The size of the blast suggests it was, as North Korea claims, a success.

North Korea's first test is largely believed to have fizzled, with a yield of less than 1 kiloton, and the second was between 2 and 7 kilotons.

"The first test almost failed. The second one showed they could basically do it. The third one showed that this is really working," said Won-Young Kim, a seismologist at Columbia University's Lamont-Doherty Earth Observatory.

The final intelligence task will be confirming or debunking North Korea's claim that this time around it tested a smaller, more advanced bomb. That is important because if the North is to field a nuclear weapon on the tip of a long-range missile, it must be lightweight. Making this determination will also depend on what materials leaked from the test, which experts can use to understand what kind of a device was detonated and infer how it was designed.

Experts have long been divided on whether North Korea has made much headway on clearing that hurdle, though the general consensus is they are not there yet. David Albright and Andrea Stricker, of the Institute for Science and International Security, said the latest test could be a measure of progress.

"Although more information is needed to make a sound assessment, this test could, as North Korea has stated, demonstrate this capability," they said in a statement. "ISIS has also assessed that North Korea still lacks the ability to deploy a warhead on an ICBM, although it shows progress at this effort."

Even so, they stressed North Korea could be years away from having a credible nuclear weapon that it could launch at the United States.

They said North Korea will need to conduct missile flight tests with a re-entry vehicle and mock warhead, increase the explosive yield of its warheads, possibly working to make them smaller, and improve the reliability of both its warheads and missiles.

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A senior Iranian commander reportedly killed

TEHRAN, Iran (AP) — An Iranian independent news website is reporting that a senior commander of Iran's powerful Revolutionary Guard has been killed in Lebanon

The website — mashreghnews.ir — says Gen. Hassan Shateri was killed by "mercenaries of the Zionist regime," but provided no details about his death.

Shateri led Guard forces in Lebanon and oversaw Iranian-financed reconstruction projects there.

Iran is a close ally of Syria and the militant group called Hezbollah, which is a powerful player in Lebanon. Tehran provides political and military support to both.

Gen. Ghasem Soleimani, the head of the Guard's Quds Force, visited Shateri's family to express his condolences.

The Quds Force oversees external operations of the Guard throughout the world.

Kerry: Response to NKorea will send Iran a message

WASHINGTON (AP) — The world must show its resolve in the face of North Korea's nuclear provocations or risk emboldening Iran, which is under scrutiny over its uranium enrichmentprogram, Secretary of State John Kerry said Wednesday.

Kerry said nations must agree on a "swift, clear, strong and credible response" to Pyongyang's thirdnuclear test and the authoritarian regime's "continued flaunting of its obligations."

In defiance of U.N. Security Council resolutions, the latest issued last month, North Korea on Tuesday detonated a nuclear device at a remote underground site. It is seen as a key step toward its goal of building a bomb small enough to be fitted on a missile capable of striking the United States.

Iran, like North Korea, is also under stiff sanctions, and negotiations with the West over its nuclear program have similarly stalled.

Iran maintains the program is peaceful, for generating energy and for medical research, not for weapons. It said Wednesday that it has begun installing a new generation of centrifuges that will allow it to vastly increase its pace of uranium enrichment in defiance of U.N. calls to halt such activities.

There has been speculation that North Korea and Iran could be cooperating on missile and nuclear development. Kerry did not draw such a connection but did say the cases were linked because they both concerned nonproliferation.

"It's important for the world to have credibility with respect to our nonproliferation efforts," Kerry told reporters after meeting Jordanian Foreign Minister Nasser Judeh at the State Department.

"Just as it's impermissible for North Korea to pursue this kind of reckless effort, so we have said it's impermissible with respect to Iran. What our response is with respect to this will have an impact on all other nonproliferation efforts."

The U.N. Security Council has issued three separate resolutions on North Korea, in response to its nuclear and missile tests since 2006. The latest resolution, which tightened sanctions, followed a December satellite launch that the U.S. says could serve to develop the North's ballistic missile capability.

The resolution warned of "significant action" if Pyongyang conducted another rocket launch or a nuclear test.

"If you are going to say things, they have to mean something. And to mean something you have to be prepared to follow up, and that's exactly what we are prepared to do," Kerry said.

European Union foreign policy chief Catherine Ashton, speaking Wednesday at the Security Council, called North Korea's nuclear test "a further blatant challenge to the global non-proliferation regime."

She said it was vital for the international community to stand united and demonstrate "that there are consequences of continued violations."

In Washington, President Barack Obama and Japanese Prime Minister Shinzo Abe consulted on a response and pledged to work together to seek action by the U.N. Security Council, the White House said.

Defense Secretary Leon Panetta said North Korea's actions represent a clear threat to the United States and undermines regional security. He vowed that the U.S. will take whatever steps necessary to meet its commitment to South Korea, including continued military exercises and increases in missile defense in the region.

Panetta said U.S. technical experts are still assessing available data to learn more about the underground explosion. That difficult task could determine whether the device was made with plutonium, of which North Korea has only limited supplies, or uranium, which can be enriched to weapons-grade in more easily concealed facilities.

"It should be of great concern to the international community that they are continuing to develop their capabilities to threaten the security, not only of South Korea, but of the rest of the world," Panetta told a Pentagon news conference. "And for that reason, I think that we have to take steps to make very clear to them that that kind of behavior is unacceptable."

The U.S. is fully prepared to deal with any contingency involving North Korea, Panetta said, and will continue to deploy forces to that region.

In an emergency session Tuesday, the Security Council unanimously said the nuclear test poses "a clear threat to international peace and security" and pledged further action. It remains to be seen, however, whether China, the North's ally, will sign on to any new, binding global sanctions.

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