A former North Korean spy says the country's leader Kim Jong-un is struggling to win his military's loyalty and is using the nuclear program to keep the public behind him.
Kim Hyun-hee, who successfully carried out a mission in 1987 to blow up a South Korean airliner, killing 115 people, says the North's leader is too young and inexperienced.
"He's struggling to gain complete control over the military and to win their loyalty," she told ABC TV's 7.30 Report on Wednesday.
"That's why he's doing so many visits to military bases, to firm up support.
"He's also using the nuclear program as a bargaining chip for aid, to keep the public behind him."
The North last week told foreign diplomats in Pyongyang they had until April 10 to consider evacuating, fuelling speculation of an imminent missile launch.
Ms Hyun-hee says she was "chosen" to become a spy for North Korea when a black sedan showed up at her school.
She was told to pack and given one last night with her family.
In 1980 Ms Hyun-hee was sent to the North's elite spy-training school, was given a new name and training in martial arts, weapons and languages.
Eight years later, she says she was personally ordered by Kim Jong-il, the father of the North's current leader, to bomb Korean Air Flight 858 in the lead-up to the 1988 Seoul Olympics.
It was a move aimed at deterring nations from competing at the Games, she said.
After boarding with a fellow spy, Ms Hyun-hee planted the bomb and got off during a stopover in the Gulf.
The bomb exploded nine hours after Flight 858 took off, as the plane was in the air en route to Seoul, leaving no survivors.
Ms Hyun-hee was later arrested as she tried to leave Bahrain using a fake passport.
After trying to commit suicide with cyanide, as an offsider succeeded in doing, Ms Hyun-hee was taken to South Korea for trial and given a death sentence.
Judged to be a victim of North Korean brainwashing, she was pardoned a few years later.
She and now lives in South Korea at an undisclosed location surrounded by bodyguards.
"I deserved the death penalty for what I did," she said.
"But I believe my life was spared because I was the only witness to this terror perpetrated by North Korea.
"As the only witness, it is my destiny to testify about the truth."