WASHINGTON >> Commentators laughed last year when a photograph emerged of Kim Jong Un standing next to an orb, which a North Korean newspaper stated was a miniaturized nuclear weapon. “That’s a weird looking disco ball,” joked one intelligence contractor on Twitter.

Not many are laughing anymore.

Today, The Washington Post reported that a U.S. intelligence assessment concluded North Korea has successfully produced a miniaturized nuclear warhead, a disclosure that rapidly intensified an already tense standoff with the rogue nation. Soon after the report, President Donald Trump warned Kim against making further threats, saying North Korea “will be met with the fire and the fury like the world has never seen.”

Whether Kim truly possesses the ability to miniaturize a nuclear warhead — and successfully launch it on an intercontinental ballistic missile — is unknown and remains hotly debated. Yet there is no doubt now that Kim has scored one major achievement: He is finally being taken seriously by the foreign policy establishment and intelligence agencies, evidenced by the latest assessment on his nuclear capabilities.

Kim came to power in 2011, and was immediately mocked for his funny haircut and pudgy appearance. Some Korea hands questioned if, at the age of 27, he could maintain his hold on power, speculating he would be dominated or pushed out by senior officials in the military.

But Kim has proven his skeptics wrong. He has eliminated potential rivals, including his uncle, whom he executed in 2013. He’s improved North Korea’s economy, in spite of international sanctions. And he’s steadily advanced North Korea’s nuclear and missile technologies, including the successful test of an ICBM on July 28 that showed a capability to travel as far as New York or Washington, D.C.

Moon Chung In, a national security adviser to South Korea’s president, said that Kim has taken rational steps to shore up his regime, with a goal of deterring any form of U.S. attack or intervention.

“North Korea is very, very stable,” Moon said during a recent interview in Seoul. “Kim Jong Un has consolidated power fully.”

Jonathan D. Pollack, a Korea specialist and senior fellow at the Brookings Institution, recalled how Sen. John McCain of Arizona this year labeled Kim Jong Un as a “crazy fat kid.” He said seeing North Korea’s leader this way is risky.

“I treat it seriously,” Pollack said of North Korea. “It’s not a cartoon because of its increasing capabilities.”

If North Korea can now claim successful miniaturization of a nuclear weapon, it would bring it a step closer to credibly threatening the United States with nuclear attack, and by the same token, being able to credibly deter any attack on its territory and the Kim regime. Yet analysts warn against exaggerating North Korea’s capabilities, noting the country’s mixed success in missile launches, and the fact that it has yet to demonstrate it can pass a missile through the upper atmosphere without damaging one of its warheads.

For many in the West, Kim’s development of nuclear weapons is the work of a deranged dictator, an image reinforced by North Korea’s bellicose messages. On Sunday, for instance, Pyongyang’s state-run KCNA news agency warned the United States against “believing that its land is safe across the ocean” with North Korea’s steady missile advances.

The warning came after the United States successfully urged the U.N. Security Council to adopt a new set of economic sanctions on North Korea.

Yet some North Korea watchers say Kim has pragmatic reasons for accelerating development of nuclear weapons. For one, he wants to be in a stronger negotiating position with the United States, its archenemy since the Korean War cessation of hostilities in 1953.

Joo Seong Ha, a North Korean defector and journalist in Seoul, said that Kim hopes to use his nuclear weapons program to leverage economic concessions from South Korea and the United States. The nuclear weapons program is “the most powerful bargaining chip that North Korea has.”

Speaking on CNN today, Sen. Chris Coons, a Delaware Democrat who sits on the Senate Foreign Relations Committee, said Kim and other North Korean leaders have been steeped in the belief that the United States is preparing to launch regime change. “I think this paranoid, militaristic and capable young leader is someone whose threats we should take very seriously.”

It’s not clear that all of Trump’s aides view Kim that way. Speaking on Fox Business on Monday, Sebastian Gorka, a national security adviser, called North Korea a “Lilliputian nation” that was engaged in bluster and blackmail.

Trump’s “fire and fury” statement also provoked a strong reaction today. McCain told an Arizona radio station that he took exception to Trump’s comments because “you’ve got to be sure that you can do what you say you’re going to do,” referencing Roosevelt’s words about walking softly, but carrying a big stick. “That kind of rhetoric, I’m not sure how it helps.”

Pollack said that Trump needs to show that he can’t easily be goaded into verbal battles with Kim. U.S. Sen. Dianne Feinstein, D-Calif., also was critical of the president’s comments.

“Isolating the North Koreans has not halted their pursuit of nuclear weapons,” said Feinstein in a statement. “And President Trump is not helping the situation with his bombastic comments.”