Even though North Korea has backed off its plans to launch a missile strike near Guam this month, it may just be a matter of time before things re-escalate.
Former Secretary of Defense William Perry says North Korea knows its army isn't as strong as others and believes a nuclear bomb would level the playing field.
Perry is one of the only Americans North Korea has ever invited to meet with its highest military leaders.
He nearly got them to stop trying to make nuclear bombs when he was there in 1990s.
"And I said why are they so important? He said for security. I said security from whom. He looked right at me and pointed at me and said "from you," says Perry.
In that time, Perry got a much better idea of how the leadership thinks and relates to the rest of the world.
It’s a completely different mindset.
Perry says North Korea worried then and worries now that the United States will try to overthrow its government so a nuclear bomb is its best defense.
He says Americans shouldn't be worried about an unprovoked attack from North Korea either on Guam or the United States.
"They're reckless, they're ruthless but they're not suicidal. They're not seeking martyrdom. They're seeking to stay in power."
What worries him is a situation where North Korea feels it's about to be attacked and worries it can't win a war. In that case Kim Jong Un may feel there's nothing to lose with nuclear war.
Perry says President Trump's recent comments warning North Korea of "fire and furry," may make the North feel less secure and thus desire nuclear missiles even more.
But he says North Korea still has a ways to go.
Perry is an expert on nuclear war and says the North already has more than a dozen nuclear weapons. But despite the country's claims, he says it doesn't have a missile to hit the United States mainland.
"Within a year or so they probably will begin to have an I.C.B.M."
Once that happens, he says it will be very hard to ever convince them to give it up and misperceived military action by the United States or another country could leads Kim Jong Un to feel just threatened enough to launch a nuclear missile.