A triumphant Kim Jong Un was crowned chairman of North ­Korea’s Workers’ Party on Monday, the climax of a once-in-a-
generation congress
during which the young leader showed how, despite the odds, he had consolidated his power.

Although he did not announce anything particularly new during the four-day meeting — espousing his usual lines about pursuing economic growth at the same time as nuclear weapons — Kim presented himself as every inch the strong leader.

With his Western-style suit and heavy-framed glasses, the 33-year-old looked the spitting image of his grandfather Kim Il Sung, North Korea’s founder and “eternal president.” State television broadcast pictures of 3,000 party members rapturously applauding a man with no military experience or revolutionary credentials, who has been in power for less than five years.

“He’s an arrogant and calculating dictator, but he’s consolidated power faster than his grandfather did,” said Katharine Moon, a Korea expert at the Brookings Institution. It took Kim Il Sung almost 25 years, until a party congress in 1960, to cement his rule.

“This guy’s managed to do it in just four years,” Moon said.

Kim took over the reins of North Korea at the end of 2011, barely a year after his father, Kim Jong Il, anointed him as his successor. In contrast, Kim Jong Il had spent more than two decades in the public eye, being groomed to inherit the leadership from his father.

Intelligence services have been predicting the imminent collapse of North Korea for years, but Kim Jong Un has defied suggestions that he’s too young and inexperienced to hold together one of the world’s most brutal dictatorships.

Kim was already head of the Workers’ Party, bearing the title “first secretary,” but was elevated — unanimously — to chairman during the highly choreographed congress. It is the same title Kim Il Sung held from 1946 to 1966.

The changes are part of a wider move by Kim to elevate the party over the military and return to the system begun by his grandfather.

The Kim family has managed to stay at the helm of the world’s only communist dynasty for 70 years through an all-pervasive personality cult that does not brook any criticism of the leadership.

That intolerance was apparent Monday when North Korea expelled a BBC journalist for writing “disrespectful” reports about the country’s leader.

Rupert Wingfield-Hayes, Tokyo correspondent for the BBC, was detained at Pyongyang airport Friday as he prepared to leave the country. after reporting on a visit by three Nobel laureates to North Korea. One of his stories described Kim as “corpulent and unpredictable.”

He was interrogated for eight hours and made to sign a statement of apology before being put on a plane to Beijing on Monday, along with two colleagues.

O Ryong Il, a spokesman for the North Korean government, said that Wingfield-Hayes was being expelled for “speaking very ill of the system” and that the government would “never admit him again into the country.”

Away from the fanfare and unflinching adulation at the congress, some analysts were not impressed at the content.

“For all the hullaballoo, there is a lot of status quo here,” said Ken Gause, a North Korea leadership expert at CNA, a research company in Arlington, Va. “We’re left wondering which of two directions he’s going in. Is he going to carry out a fifth nuclear test, or is he going to try to continue pursuing a peace agreement with the U.S.?”

During a three-hour-long address to the congress, Kim repeatedly promoted his “byungjin” policy, the “simultaneous pursuit” of both economic development and nuclear weapons. He presented a five-year economic plan, the first from North Korea in three decades.

But as he touted nuclear weapons, Kim said also his country would not use them unless its sovereignty was challenged. And he struck a surprisingly conciliatory note on South Korea, suggesting that he was trying to dial back recent tensions.

He also hinted at the possibility of a peace treaty with the United States, saying that Pyongyang was open to normalizing relations with “once hostile” nations.