Kim Jong Un compelled to prove he's tough: U.S. intelligence

(CBS News) -- North Korea moved a missile to its east coast Thursday, possibly putting its neighbors -- but not the United States -- within range.

Satellite photos show new activity at a North Korean nuclear reactor used to make fuel for bombs.

It was another day of belligerent threats from a new dictator who may be as young as 29.

Kim Jong Un says he is ready to attack the U.S. According to a psychological profile put together by U.S. intelligence, Kim Jong Un may feel compelled to prove just how tough he is to make up for his inexperience.

The two previous North Korean dictators were Kim Jong Un's grandfather, Kim Il Sung, a hard core revolutionary, and his father, Kim Jong Il, who ruled for 17 years.

But unlike them, Kim Jong Un knows nothing about hardship and power struggles.

One of the CIA's former top experts on North Korea, Joseph DeTrani, described Kim Jong Un as very young.

"A Kim who was not, did not, prepare very well for the position," said DeTrani.

DeTrani has tracked Kim Jong Un from his prep school days in Switzerland, through his sudden ascension to power after the death of his father.

"He is a man who is 28, 29 -- very limited exposure to the west, to China also, so he's lived in a closed environment," said DeTrani.

With a stylish wife, Kim Jong Un looked more moderate, but instead he has been acting like a man with something to prove to his own military.

"I think he would have to be somewhat sensitive to how these people view him as a leader," said DeTrani.

"The sense is he's emulating his grandfather, Kim Il Sung."

Kim Il Sung invaded South Korea in 1950, setting off three years of war and six decades of hostile truce that Kim Jung Un is pushing to the breaking point.

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The only country that has any real sway over North Korea is China. China is doing two things: One, it's urging both sides -- the U.S. and North Korea -- to tone it down; and two, it is making sure North Korea understands if it creates an incident in which South Korean citizens are killed, the U.S. and South Korea are likely to launch a major attack against the north.

You can't say North Korea is toning down its rhetoric, but it does seem to have gotten the message about the potential consequences of an incident because so far, there have been no threatening troop movements.