Skeptics of North Korea’s nuclear threat, and there are many, have long clung to two comforting assurances.

While the North has the bomb, it doesn’t have a warhead small enough to put on a long-range rocket. And it certainly doesn’t have a re-entry vehicle to keep that warhead from burning up in the atmosphere before it could reach threatened targets, for example Manhattan.

But today North Korea suggested it would soon be ready to show the world it has mastered both technologies.

This may be just the latest case of Pyongyang’s propaganda, but if true it would represent a huge advance in the country’s suspected nuclear capabilities, and undermine suggestions that its claims are all bluff and bluster.

“We have proudly acquired the re-entry technology, possessed by a few countries styling themselves as military powers,” said North Korean leader Kim Jong-un in state-run media.

The authoritarian leader was said to have made the comment after meeting scientists and technicians following, what it claimed, was a successful test of a re-entry vehicle.

Kim ordered preparations for a “nuclear warhead explosion test” and test-firings of “several kinds of ballistic rockets able to carry nuclear warheads”, the report added.

With no way independently verifying any of these claims, it’s difficult to separate Pyongyang’s rhetoric from its reality.

Nuclear arsenal

Kim’s most likely candidate for an intercontinental ballistic missile is KN-08, or the Hwasong as it is known in North Korea. The three-stage rocket has an estimated range of 5,000-6,000km (3,100-3,700 miles), but could be modified to increase this.

That range would be ample for attacks on US military bases in Japan, but not New York.

But a militarised version of the rocket used to put a North Korean satellite into orbit last month is believed to have potentially a much longer range – one that could reach the US mainland.

When a new version of the KN-08 was displayed at a military parade in North Korea in October, military experts at Jane’s defence weekly said it featured a smaller, blunter warhead shape “that could confirm US intelligence assessments and North Korean claims of success in miniaturising its nuclear warheads”.

But the Pentagon has often expressed doubt over the reliability of the KN-08 because North Korea has never tested it “end-to-end” – from launch through re-entry and warhead delivery – to prove that it works.

Just last week, photos of Kim splashed across the front page of the ruling party’s Rodong Sinmun newspaper showed him standing in a hangar filled with ballistic missiles, inspecting a disco ball-sized silvery orb.

Experts said the object looks very much like a credible nuclear weapon, though it was clearly a mock-up of whatever device the North may have – Kim wouldn’t have stood so close to the real thing without radioactivity protection gear, nor would he have been holding a lit cigarette.

North Korea’s message, however, was obvious: we know what you think our weaknesses are, but don’t be so sure.

“Every time the North Koreans test another bomb or a missile, I get calls asking what message the North Koreans are trying to send,” wrote nuclear expert Jeffrey Lewis for Foreign Policy magazine.

“Well, let’s see: they’ve paraded two different ICBM [inter-continental ballistic missiles] through Pyongyang, conducted four nuclear tests, showed us a compact nuclear design sitting next to a modern re-entry vehicle in front of one of those ICBMs, and hung a giant wall map of the United States marked with targets and titled ‘mainland strike plan,’” he said.

“Here’s a wild guess: they are building nuclear-armed ICBMs to strike the United States! Why is this so hard to grasp?”



They are building nuclear warheads to strike the United States Jeffrey Lewis

The timing of Pyongyang’s recent moves is crucial. The regime faces a new UN sanctions package after its 6 January nuclear test, which it claimed was an “H-bomb”, and has significantly amped up its rhetoric while the US and South Korea carry out annual joint military exercises.

Cause celebre

The country is also conducting a 70-day “loyalty campaign” ahead of a once-in-a-generation ruling party congress in May. The congress could be something of a coming-out party for Kim, allowing him to emerge from the shadows of his father and grandfather and establish himself more firmly as North Korea’s supreme leader.

He could also lay out his own long-term domestic and international agenda. Kim presumably wants to face this from a position of power and making nukes his cause celebre serves that purpose.

Standing firm on nukes bolsters his credibility with hard-liners in the military and reinforces his regime’s defiant, dangerous reputation against its key antagonists.

US-South Korea joint military exercises in the Korean peninsula Photograph: Jeon Heon-Kyun/EPA

It also has domestic propaganda value, showing how North Korea, singlehandedly and against all odds, can make breakthroughs few countries have accomplished.

Of course, that logic breaks two ways: if the country hasn’t made major advances, exaggerating them is the next best thing.

But Lewis and other experts have expressed concern that Washington, in particular, has a pattern of not taking the North’s purported capabilities seriously enough.

While it might declare success prematurely, as with the recent H-bomb claims, North Korea has an established track record of getting there eventually.