NEW YORK, Jan. 20 (UPI) -- A former U.S. defense secretary called Kim Jong Un "dangerous" and "stupid" while warning North Korea is perilously close to obtaining submarine-launched missile technology, or SLBM.
"[They're] working on submarine-launched ballistic missiles and that capability. And, you know, they have these successive failures, but eventually they're going to get it right. And that's going to be a very dangerous situation," said Robert Gates, during a discussion at the Council on Foreign Relations Wednesday.
Gates also said Kim is not only dangerous but also stupid, adding, with "each successive generation [of Kims] we've been swimming in a shallower and shallower part of the gene pool."
The former defense secretary added Kim was behind the sinking of the South Korean warship Cheonan in 2010, and that he was a "leading figure" behind the bombardment of Yeonpyeong Island, although Kim, at the time, was not in power.
"He was basically trying to prove his mettle to the North Korea leadership, that he was tough enough to take on the job," Gates said.
On China, Gates said that Xi Jinping is undoubtedly in control of the military, and that command and control of the People's Liberation Army has been tightened.
China's leverage over the North Korea leadership, however, may be waning.
Pyongyang conducted a fourth nuclear test on Jan. 6, despite Beijing's calls for denuclearization on the peninsula.
The souring of relations, however, has not impeded trade along the China-North Korea border.
The North Korean port city of Rajin is emerging as a logistics hub for Chinese freight from the country's northeast that's headed for China's southeast by ship.
Voice of America reported the Chinese border city of Hunchun permitted a total of 8,600 tons of cargo to cross into North Korea. The shipments are worth $2.8 million.
China is North Korea's most important trading partner, and Beijing has been reluctant to cut down trade ties despite recent events.