By declaring war on South Korea, he seems to be channeling his firebrand grandfather, Kim Il Sung, the iconic founder of North Korea who plunged the region into a war that killed as many as 5 million people, including 35,500 American troops, in the 1950s. U.S. officials are on alert for a new provocative act tied to the elder Kim's birthday, which is widely celebrated in North Korea, on Monday.
As Kim Jong Un eases into the top job of a nation whose elite has long been presumed to be rife with intrigue and rivalries, he appears determined to assert a tight grip on the levers of power.
"He has an inferiority complex," said Kongdan Oh Hassig, a North Korea expert at the Institute for Defense Analyses in Alexandria, Va. "He is trying to show that he has a strategic mind, that the military stands behind him and that no one stands against him."
There are major gaps in the public biography of the new leader, the third son of Kim Jong Il. But as he has assumed an increasingly public role, Kim Jong Un's portrait has become a bit sharper, revealing a study in contrasts that has captured the world's undivided attention.
As a child, Kim was impetuous and competitive to a fault, according to a 2003 memoir by the family's former sushi chef, writing under the pseudonym Kenji Fujimoto. The book offered a rare peek into one of the world's most secretive and consequential families. Kim Jong Il adored his tempestuous son, according to Fujimoto, perhaps seeing in him the steely resolve that has kept the family firmly in control of the pariah state since its creation in 1948.
Using a fake name and pretending to be the son of a North Korean diplomat, Kim Jong Un in 1998 was enrolled in a private school in a sleepy Swiss town, where he spent at least two years. Classmates have been quoted describing him as a good pupil who exhibited an ardent fascination with American basketball — one that extends into adulthood, as evidenced by his hosting of the former NBA star Dennis Rodman earlier this year. In 2000, he vanished from the school without saying goodbye, and little is known about his later teenage years.