Nuclear weaponsN. Korea’s test of miniaturized warhead, submarine-launched ballistic missile, are game changers

North Korea has conducted its fifth nuclear test last night, marking the 68th anniversary of the nation’s founding.

Military analysts say the test shows a worrisome improvement in North Korea’s nuclear capabilities:

• It was the most powerful nuclear test to date. The yield of the explosion was about ten kilotons – slightly smaller than the yield of the bomb dropped on Hiroshima, estimated to have been between twelve and eighteen kilotons. The U.S. Geological Survey said the test triggered a magnitude 5.3 earthquake. Some analysts suggested the bomb’s yield could be significantly higher than ten kilotons. “That’s the largest DPRK [Democratic People’s Republic of Korea] test to date, 20-30kt, at least. Not a happy day,” Jeffrey Lewis of the California-based Middlebury Institute of International Studies said. “Yield estimates are always kind of approximate. The point is that it is the biggest one to date unless they revise the yield downward,” he told the Guardian.
• The warhead tested in the explosion was miniaturized, indicating that North Korea now has the capability to mount a nuclear warhead on a missile. If North Korea could put such a missile on a mobile launcher, it would make any effort to keep tab on the country’s nuclear capabilities – or target them in a war – much more difficult. The North Korean KCNA official news agency said: “This [test] has definitely put on a higher level … DPRK’S [North Korea’s] technology of mounting nuclear warheads on ballistic rockets.”

CNN notes that the nuclear test drew immediate condemnations.

Barack Obama, who was on Air Force One on his way back to the United States from his Asia tour, said provocative actions by North Korea would have “serious consequences.”

“To be clear, the United States does not, and never will, accept North Korea as a nuclear state,” Obama said. He said he would work “to take additional significant steps, including new sanctions, to demonstrate to North Korea that there are consequences to its unlawful and dangerous actions.”

On Thursday, a day before the test, Obama had expressed concern about North Korea’s nuclear activity. “We are going to make sure that we put our defensive measures in place so that America is protected, our allies are protected,” he said in a meeting with South-east Asian leaders in Laos. “We will continue to put some of the toughest pressure that North Korea has ever been under as a consequence of this behavior.”

Japan called for an emergency meeting of the UN Security Council, with Prime Minister Shinzo Abe describing North Korea’s nuclear weapons program as a “grave threat” to Japan.

Japan’s government spokesman, Yoshihide Suga, described North Korea as a “neighborhood outlaw.”

China, North Korea’s ally, expressed its “firm opposition” to the nuclear test. “We strongly urge [North Korea] to honor its commitment to denuclearization, comply with relevant UN Security Council resolutions, and take action to stop the situation from deteriorating,” China’s Foreign Ministry said.

South Korean president Park Geun-hye said the test as a clear violation of Security Council resolutions banning the North from developing nuclear and other weapons of mass destruction. Park accused Kim of “maniacal recklessness” in his pursuit of building a viable nuclear arsenal.

The previous four North Korean nuclear tests were conducted in 2006, 2009, 2013, and 2015. The North Koreans said that the January 2015 test was a test of a hydrogen bomb, but nuclear experts expressed their doubt of that claim.

Last month, the North successfully test-fired a ballistic missile from a submarine, a major step in building a nuclear launch capability which is nearly impossible to detect and thwart.

Military analysts note that last night’s test of a miniaturized warhead with a near-Hiroshima yield, together with North Korea’s proven progress in launching ballistic missile from submarines, mean that the country is getting closer to possessing a nuclear arsenal capable of hitting the United States.