North Korea says it successfully tested a hydrogen nuclear bomb, a development that, if true, represents a dramatic advance in its military capabilities. Previously, the nation has tested plutonium weapons in three underground nuclear tests, but hydrogen bombs are much more powerful.
Around 10 a.m. local time on Wednesday, an earthquake was detected near North Korea’s nuclear test site, sparking concern that the nation had conducted a fourth nuclear test. A short time later, a statement was read on North Korean state TV claiming that the nation detonated a “miniaturized” hydrogen nuclear bomb, and the test was a “perfect success.” “If there’s no invasion on our sovereignty we will not use nuclear weapon,” the statement said. “This H-bomb test brings us to a higher level of nuclear power.”
Statements from North Korea are notoriously untrustworthy — last summer the nation claimed to have invented a vaccine for Ebola, HIV, and “a number of cancers” — but obviously this is a concerning development. Here’s what we know so far.
Did North Korea actually test a hydrogen bomb?
It seems highly likely that North Korea conducted some kind of nuclear test, but no one has independently verified that the weapon tested was in fact a hydrogen bomb — or, as North Korea described it, an "H-bomb of justice." And, experts are massively doubtful about the whole thing.
Or, as White House spokesperson Josh Earnest put it on Wednesday afternoon, there is “significant and understandable skepticism of the claims of the North Korean regime.”
The U.S. Geological Survey measured Wednesday morning’s seismic activity, which took place northeast of Sungjibaegam, at a magnitude of 5.1, and South Korean experts said it appeared the quake was caused by a man-made explosion. A 4.9-magnitude earthquake was recorded near the same spot before North Korea confirmed its last nuclear test in 2013.
People were evacuated from buildings after tremors from the explosion were felt in the Chinese border town of Yanji:
Recent satellite photos analyzed by 38 North, a Washington research institute that follows North Korea’s nuclear activity, showed evidence that the nation has been digging a new tunnel at its nuclear test site. Jeffrey Lewis, a nuclear expert at the Middlebury Institute of International Studies in Monterey, California, said last month that the tunnel made it “more likely that they will conduct a test in the coming year.” But he told the Washington Post that Wednesday’s blast wasn’t drastically bigger than in previous tests, suggesting it wasn’t a hydrogen bomb.
The South Korean defense ministry said it can’t confirm what kind of event occurred, and a senior U.S. administration official told CNN that it may take days to obtain scientific data that can determine whether the test was successful.
South Korean lawmaker Lee Cheol Woo told the AP that he was told that the seismic wave caused by the test was small enough that people were skeptical that it could have been caused by even a failed hydrogen-bomb test.
For what it’s worth, here’s the announcement that aired on North Korean TV:
Why is this different from North Korea’s previous weapons tests?
In the past, North Korea has only tested bombs that use fission to break the atomic nucleus of elements like plutonium, releasing large amounts of energy. A thermonuclear bomb uses fusion to combine small atoms, such as hydrogen, creating a much larger blast. A fission weapon typically yields around ten kilotons, while a fusion weapon is measured in megatons (1,000 kilotons). If North Korea has a true hydrogen weapon, it would be hundreds of times more powerful than the bombs dropped on Hiroshima and Nagasaki.
North Korea’s development of a hydrogen bomb is also concerning because fusion weapons are much harder to make. Some experts believe Pyongyang may already have 10 to 15 atomic weapons, but the bombs are rudimentary. In May, it claimed to have developed miniaturized nuclear weapons, which could be delivered via missile, but many were skeptical. As the Associated Press notes, a successful test of a hydrogen bomb would mean that North Korean engineers are much closer to their stated goal of creating a stockpile of nuclear-tipped missiles that can reach the U.S.
North Korean leader Kim Jong-un claimed last month that his scientists were developing a hydrogen weapon, but Bruce Bennett, a senior defense analyst at the nonprofit Rand Corp., suggests that he may only have “boosted” weapons. As Bennett explains in a CNN opinion piece, that’s a far more plausible possibility, considering that North Korea only conducted its first nuclear test in 2006:
En route to the development of fusion weapons, some countries develop so-called “boosted” weapons, which use a small amount of fusion to boost the fission process, causing more large atoms to fission and thus releasing more energy — initially, perhaps a weapon of 50 kilotons or so. Because some fusion is involved in such a weapon, Kim may be claiming that he has achieved a hydrogen bomb when in practice he only has a boosted weapon.
What difference would a boosted nuclear weapon make? If North Korea really has a boosted nuclear weapon of perhaps 50 kilotons, it could do significant damage in a city as densely populated as Seoul, South Korea: About 250,000 people could be killed in such a strike, or about 2.5% of the population. This would mark a genuine advance in the level of damage that North Korea is capable of doing. And if North Korea one day produces a true hydrogen bomb of, say, one megaton yield, then it would be deadlier still.
Bennett added to the BBC, “The bang they should have gotten would have been 10 times greater than what they’re claiming. So Kim Jong-un is either lying, saying they did a hydrogen test when they didn’t, they just used a little bit more efficient fission weapon — or the hydrogen part of the test really didn’t work very well or the fission part didn’t work very well.”
How are other nations responding?
The South Korean government convened an emergency meeting of its National Security Council. “This is a grave provocation to our security, threatening the survival and future of our nation and further directly challenging peace and stability in the world,” said South Korean president Park Geun-hye. “The government — in close cooperation with the international community — should have North Korea pay a price without fail for the latest nuclear test.”
Regardless of whether North Korea tested an H-bomb or conducted a smaller nuclear test, the world is very mad at Kim Jong-un.
Several other nearby nations held emergency meetings as well, and Japanese prime minister Shinzō Abe issued a statement condemning the test. “The nuclear test that was carried out by North Korea is a serious threat to the safety of our nation and we absolutely cannot tolerate this,” he said. “This clearly violates U.N. Security Council resolutions and is a grave challenge against international efforts for non-proliferation.”
Although China is an ally, they were also not impressed by North Korea’s bragging — and were not warned about the test in advance. A spokesperson at the Chinese Ministry of Foreign Affairs told reporters, “China is strongly against this act.” North Korea’s only friend is probably getting pretty incensed at this point. As The Guardian points out, “Kim has refused to rejoin the Chinese-led six-party nuclear talks. In September, he snubbed President Xi Jinping’s invitation to attend celebrations marking the end of the second world war.”
The New York Times adds that it was never surprising that North Korea was far less interested in taking part in international nuclear agreements than Iran:
From Pyongyang’s viewpoint, there is little incentive to give up the nuclear arsenal. The world is not exactly banging on North Korea’s door to do business the way it wants to resume relations with Iran: The North has no oil, no striving middle class, and little strategic value in the modern world. Its greatest power is the threat it poses to one of the most prosperous corners of the globe.
One analyst at the New Zealand Contemporary China Research Centre at the Victoria University of Wellington told the Washington Post, “In a way, this is a protest against Beijing. They are saying: ‘we can do whatever we want. This shows our independence and we don’t need your approval.’”
Russia wants everyone to chill out for a minute, in case North Korea didn’t actually test a hydrogen bomb. The foreign ministry called on “all interested sides to preserve maximum restraint and to not take actions that could rouse the uncontrolled growth of tensions in Northeast Asia,” per the AP.
The United Nations Security Council said it would meet on Wednesday, at the request of Japan and the United States. The 15-nation council put North Korea under sanctions after its first nuclear test, and if a fourth nuclear test is confirmed it’s likely the penalties will be increased.
The White House National Security Council released this statement:
State Department spokesperson John Kirby added, according to the Washington Post, “We have consistently made clear that we will not accept it as a nuclear state. We will continue to protect and defend our allies in the region, including [South] Korea, and will respond appropriately to any and all North Korean provocations.”
Marco Rubio was the first GOP presidential candidate to weigh in, offering this predictable assessment:
Senator Ted Cruz also blamed Obama and Hillary Clinton for the nuclear test, and then drew his own conclusions for what this all meant for Iran. "We saw last night the consequences of this deal if it is allowed to go forward," he said, according to the Washington Post. "[Iran’s] nuclear test may not be underground, measured by an earthquake. It may be above the skies of Tel Aviv, or New York, or Los Angeles."
Donald Trump later added that North Korea was a problem that China should deal with. He also offered his analysis of Kim Jong-un, calling him a "madman."
"And nobody talks to him, other than of course Dennis Rodman. That’s about it."
Hillary Clinton responded to the incident by drawing eyes back to her résumé. "As secretary, I championed the United States’ pivot to the Asia Pacific — including shifting additional military assets to the theater — in part to confront threats like North Korea and to support our allies," she said in a statement.
Why would North Korea conduct a test now?
Sussing out Kim’s motives is nearly impossible, but we do have some clues about the timing. Friday is the leader’s 33rd birthday, and new nuclear capabilities are the perfect gift for a dictator. It’s also possible that Kim wants a major accomplishment to brag about in May, when the Korean Workers’ Party holds its first Communist Party congress in 36 years.
Phil Robertson at Human Rights Watch thought these were lousy reasons to conduct a test.“Kim Jong-un may think it appropriate to celebrate his birthday early with a nuclear test, but even a hydrogen bomb should not cause the world to forget that the Kim family’s hereditary dictatorship is built on the systematic brutalization and abuse of the North Korean people,” he said in a statement.
Kim may also be anxious about North Korea’s shaky ties to China, its last major ally, though the move is likely to worsen their relationship even further. Spokesperson Hua Chunying said China “firmly opposes” the purported hydrogen-bomb test, adding, ”North Korea should stop taking any actions which would worsen the situation on the Korean peninsula.”
North Korea offered a poetic explanation for its latest act of defiance. The televised statement said that for North Korea to give up its nuclear weapons program while the U.S. continues its "hostile policy" would be "as foolish as for a hunter to lay down his rifle while a ferocious wolf is charging at him." According to Shanghaiist, the state media agency, KCNA, added that any nuclear weapons tested were "self-defense against the US having numerous and humongous nuclear weapons."
KCNA also noted that "The U.S. is a gang of cruel robbers which has worked hard to bring even a nuclear disaster to the DPRK, not content with having imposed the thrice-cursed and unheard-of political isolation, economic blockade and military pressure on it for the mere reason that it has differing ideology and social system and refuses to yield to the former’s ambition for aggression."
The L.A. Times talked to Bonnie Glaser at the Center for Strategic and International Studies, who "recalled one official saying that U.S. bargaining in the past had taught Pyongyang that it was ‘OK to pee on the rug’ and what was necessary now was to not get hysterical every time they ‘engage in bad behavior’ by going back with a fresh package of proposals."
Regardless of what the next year brings — does the U.S. try to talk it out with Kim? — it seems clear that North Korea has invited the world to invent new ways to sanction it, which will give the country plenty more reasons to hate the rest of the world.
This post has been updated throughout.