What’s more, there’s a lot to indicate that North Korea isn’t close enough to developing ICBM-capable missiles to strike the United States even if it wanted to. The panic over North Korea’s missiles was elevated recently when leaked classified U.S. intelligence estimates were reported to indicate that Pyongyang has already achieved such capabilities, in addition to possessing as many as 60 nuclear weapons in its arsenal. But I don’t concur with those estimates.

Based on my 50 years of experience with nuclear technologies and nuclear weapons, combined with what I saw and learned during my seven visits to North Korea beginning in 2004, I don’t believe Pyongyang has yet mastered the key elements of delivering a nuclear-tipped ICBM to the continental United States. Although North Korea demonstrated significant progress in the missile field with two launches in July, experts have raised serious questions about whether it has demonstrated all the missile and re-entry vehicle technologies that will protect the nuclear warheads during the fiery plunge into the Earth’s atmosphere.