Story highlights

North Korea claimed this week to have tested a hydrogen bomb

Joe Cirincione: North Korea may actually have been testing something in between an A-bomb and an H-bomb

Editor’s Note: Joe Cirincione is the president of Ploughshares Fund, a global security foundation. He is the author of “Nuclear Nightmares: Securing the World Before It Is Too Late,” and “Bomb Scare: The History and Future of Nuclear Weapons.” He serves on the secretary of state’s International Security Advisory Board. The views expressed are his own.

CNN  — 

The bad news is North Korea just tested another nuclear weapon, in flagrant violation of the global norm against such tests observed by all other nations since 1998.

The good news is that whatever their intentions, they do not appear to have succeeded with the test. Contrary to the global headlines generated by their announcement, North Korea does not have an hydrogen bomb. Nor does it appear that they have significantly advanced their abilities since their last test in 2013.

Joe Cirincione

Early indications are that the test had a yield of about 6 kilotons, or the explosive force of 6,000 tons of TNT. That is a smaller yield than North Korea’s last test. Even a failed H-bomb test would have resulted in an explosion of 10 to 50 kilotons.

This is likely why White House spokesman Josh Earnest said Wednesday that data from monitoring stations is “not consistent with North Korean claims of a successful hydrogen bomb test.” Earnest concluded that there’s “nothing that’s occurred in the last 24 hours that has caused the United States government to change our assessment of North Korea’s technical and military capabilities.”

We will know more in a few days as data comes in from the global sensor network maintained by the Comprehensive Test Ban Treaty Organization. Their instruments, which have already measured the seismic shock of the test, will pick up radionuclide traces that should give us a good idea of exactly what kind of explosion this was.

Why does this matter? Aren’t atomic bombs bad enough?

Yes, but hydrogen bombs are worse. They are many times more powerful than an atomic bomb. Atomic bombs get their power from the splitting of the atom. This fission turns a small amount of matter into pure energy.

A hydrogen bomb is basically two bombs in one. It uses the heat, radiation and pressure from an atomic bomb to fuse atoms together, reproducing the fundamental energy source in the universe – the fusion reactions that power our sun and all other stars.

But when we create a piece of the sun on the surface of the Earth, it also produces death on a massive scale. Fusion reactions release many times the energy of a fission reaction. The atomic bomb used on Hiroshima was about 15 kilotons of explosive force. In contrast, the United States exploded the world’s first H-bomb in 1952 with an explosive yield of 10 megatons, or 10 million tons of TNT – that is almost a thousand times more powerful that the Hiroshima bomb.

Robert Oppenheimer, the head of the Manhattan Project, which developed the world’s first nuclear weapon, initially opposed the H-bomb, calling it a “weapon of genocide.”

But all the nations that could build H-bombs did so. The United States, Russia, France, the United Kingdom and China have all tested thermonuclear weapons, and H-bombs now make up the majority of the weapons in their arsenals.

India claimed to have successfully tested an H-bomb in the late 1990s, but like the North Korean test, that claim has proved to be highly suspect. Experts have argued for years about whether Israel possesses thermonuclear weapons or just the ability to make them should it want to.

North Korea may have been testing something in between the A-bomb and H-bomb, a “boosted” weapon. This basically adds a small amount of tritium, a hydrogen isotope, to an atomic bomb assembly.

The atomic explosion fuses some of this hydrogen, releasing a flood of neutrons that accelerate the fission process, squeezing out more yield from a given amount of a nuclear fuel. This can help reduce the size of a weapon while keeping the yield high. That may have been what the North Koreans were trying to achieve as it could help them shrink the size of the warhead so that it could fit onto the nosecone of a missile.

Even this seems to have failed, as the test had a smaller, not larger, yield than the 2013 test. But because the device may have used hydrogen as part of the explosion, the North Koreans can claim it was a “hydrogen” bomb.

Of course, exaggerated claims are the norm for this self-obsessed regime.

Last year, North Korea claimed to have successfully test fired a submarine-launched ballistic missile in the waters off North Korea. But on closer examination, it turns out that they actually only staged an “ejection test,” popping up the first stage of a missile from under the water. It traveled about 100 yards before falling back into the sea.

Although North Korea does not actually have an H-bomb, its bravado has triggered a global reaction as if it did. Even its closest ally, China, is furious. Every test, even failed ones, advance North Korea’s capabilities. And the reality is that if not stopped, North Korea’s leaders may one day get the most destructive weapon ever created.

Nuclear policy experts can seem like Cassandra, constantly prophesizing apocalyptic futures. In case you haven’t noticed, we don’t live in a Mad Max world devastated by nuclear war. Terrorists have not blown up New York with a makeshift nuclear bomb. We haven’t bankrupted ourselves, despite the trillions of dollars spent on Cold War weapons.

Join us on
Read CNNOpinion’s Flipboard magazine.