China and South Korea joined Friday in warning of North Korea’s advances in nuclear technology that the U.S. commander in South Korea has said could include the miniaturization of a weapon for a missile warhead.
After talks in Beijing, the nuclear envoys of China and South Korea agreed to cooperate in efforts to rein in North Korea’s nuclear weapons programs, South Korea’s Yonhap news agency reported.
“We exchanged deep concern about North Korea's advances of nuclear and missile capabilities and, with a sense of urgency, agreed to continue to make close cooperation to curb such advances," Hwang Joon-kook, South Korea’s chief nuclear envoy, told reporters.
Hwang’s comments after meeting with his Chinese counterpart, Wu Dawei, came a week after Army Gen. Curtis “Mike” Scaparrotti warned of the possibility that North Korea had the capability to miniaturize a nuclear weapon for a missile nosecone.
“I believe they do” know how to make a small warhead, said Scaparrotti, commander of U.S. Forces Korea and the Korea-U.S. Combined Forces Command. “I’m not saying that I know that by any factual basis, but I believe they probably have the background to do this,” Scaparrotti said at a Pentagon briefing.
“I’m just saying as a commander, I’ve got to assume they have the capabilities to put it together,” Scaparrotti said. “We’ve not seen it tested at this point and as you know, for something that complex, without it being tested, the probability of it being effective is pretty darn low.”
However, the ability to reduce the size and weight of a nuclear weapon to fit inside a ballistic missile warhead required advanced testing and exacting engineering, and it was doubtful that North Korean technicians were close to attaining those goals, according to nuclear weapons specialists.
“For him (Scaparrotti) to be correct would imply significant progress over the last year” by North Korean technicians, said Hans Kristensen, a nuclear arms analyst at the Federation of American Scientists.
“Overall, the U.S. intelligence community does not agree with the assessment” that the North Koreans have made significant progress on miniaturization, Kristensen said.
Kristensen said that the U.S. required “many nuclear tests to perfect a design” for a nuclear missile warhead, and there was no evidence that the North Koreans had conducted similary tests. “That’s why I’m very skeptical,” Kristensen.
A different view was offered by Mark Fitzpatrick, director of the Non-Proliferation and Disarmament Program at the International Institute for Strategic Studies (IISS).
Fitzpatrick told the Yonhap news agency that: "My analysis is that North Korea could probably miniaturize a warhead that should fit for a Rodong missile," a medium range ballistic missile developed by North Korea.
Fitzpatrick said it was "logical that [the North Koreans] would be making progress in being able to produce the miniaturized warhead," but he also noted the need for extensive testing.
"Probably, the North knows how to do it based upon their technical abilities, but until they test the miniature warhead, they would not be sure,” Fitzpatrick said. “In the process of the warhead development, it takes several tests to get it right.”