A North Korean official told a delegation of Japanese academics that North Korea will test a nuclear weapon. The Washington Post reports:

Yasuhiko Yoshida, a former U.N. proliferation expert and North Korea specialist at Osaka University of Economics and Law, said in a telephone interview that he had held two discussions on May 3 with North Korean officials at the Institute for Disarmament and Peace, a Pyongyang think tank linked to the North Korean Foreign Ministry. Yoshida said the key comment came during the second discussion—a phone call from the institute’s deputy director, Pak Hyon Jae, who Yoshida said used studied language and spoke through an interpreter. Pak, according to Yoshida, said a North Korean nuclear “test is indispensable,” adding, “You’ll find that out soon.”

The Post added that “word of the new North Korean threat came even as the Pyongyang government appeared to hint … that it may be willing to return, under certain conditions, to multilateral talks aimed at its nuclear disarmament.”

Threat?

The Oxford English Dictionary defines a “threat” as “a declaration of hostile determination or of loss, pain, punishment, or damage to be inflicted in retribution for or conditionally upon some course … The radical sense appears to be ‘pressure applied to the will by declaration of the harm that will follow non-compliance’. It is thus indirect compulsion.”

I think this is a clear statement of an intent to test, full-stop.

Reporters have dutifully demurred that this may be a bluff. I don’t buy it. My guess is that Pyongyang has set in motion a process that will be very hard to turn back. I am not sure that a competent and vigorous administration could get this horse back in the barn (although it would be nice to have such an Administration to give it the old college try).

The intelligence community, according to press reports, has been accumulating evidence of North Korea’s intent to test a nuclear weapon. The New York Times recently reported:

White House and Pentagon officials are closely monitoring a recent stream of satellite photographs of North Korea that appear to show rapid, extensive preparations for a nuclear weapons test, including the construction of a reviewing stand, presumably for dignitaries, according to American and foreign officials who have been briefed on the imagery. [Emphasis mine]

Wow, how bad do you have to screw up to be assigned to observe the inaugural North Korean nuclear test? Maybe we’ll know Kim is bluffing by the invitations. How much prior notice does etiquette demand for dignataries invited to an NPT-violating nuclear test? Can we assume cheap cardstock indicates a bluff? Why do you get Arms Control Wonk when you need Miss Manners?

The New York Times has a video of David Sanger talking more specifically about the trench and viewing platform under construction. Sanger implied the North Koreans have drilled horizontal shaft into a mountain, while AP implied that a vertical shaft. Neither was presumably optimizing for an audience that knows the difference (and cares).

The Office of Technology Assessment explains the difference in terms of the US program:

Presently, an average of more than 12 tests per year are conducted at the Nevada Test Site. Each test is either at the bottom of a vertical drill hole or at the end of a horizontal tunnel. The vertical drill hole tests are the most common (representing over 90% of all tests conducted) and occur either on Yucca Flat or, if they are large-yield tests, on Pahute Mesa. Most vertical drill hole tests are for the purpose of developing new weapon systems. Horizontal tunnel tests are more costly and time-consuming. They only occur once or twice a year and are located in tunnels mined in the Rainier and Aqueduct Mesas. Tunnel tests are generally for evaluating the effects (radiation, ground shock, etc.) of various weapons on military hardware and systems.

The North Koreans, of course, could use either for a simple fission device or something small enough for a Taepo Dong 2. My curiosity is just that: curiosity.

The Pakistanis apparently used both vertical and horizontal shafts for tests. ISIS has before and after pictures of the Pakistani site.

Paul Adds:

A similar, but more credible, source indicates that North Korea is not going to test. In a 19 April Hankyoreh Shinmun Seoul article, Selig Harrison describes a meeting with President of the Supreme People’s Assembly Kim Yong Nam and a high-ranking North Korean general:

When I asked Kim Yong Nam how he knew North Korea’s nuclear weapons would work in the absence of a test, he replied, “The agencies concerned are convinced that they have all the preparations made properly, and that our nuclear weapons are operational.” But General Ri Chan Bok said, “there’s no need for a test, and we don’t want to have one, even one underground, because of the fallout. Without a test, our nuclear deterrent will be functional. We are ready to put warheads on our missiles whenever we want.”