(BBC News) In August last year, Thae Yong-ho became one of the highest-ranking officials ever to defect from North Korea. In a wide-ranging interview in Seoul, he tells the BBC's Stephen Evans he believes leader Kim Jong-un would be prepared to attack the US with nuclear weapons, but that the regime will one day fall.
There are moments when the usually fluent English of the North Korean defector halts. His voice quivers and he pauses. His eyes grow moist.
These moments of silent emotion come when Thae Yong-ho thinks about his brother back in North Korea.
Advertisement - story continues below
He told the BBC that he was sure that his family have been punished for his defection. This realisation both grieves him and steels him against the regime.
"I'm sure that my relatives and my brothers and sisters are either sent to remote, closed areas or to prison camps, and that really breaks my heart," he said.