ANALYSIS:
Thermonuclear North Korea –
The Threat and Response
On September 3, at exactly noon local time, North Korea detonated its sixth nuclear device purportedly releasing 140 kilotons of TNT equivalent, according to a recent US intelligence estimate, and almost ten times greater than the U.S. nuclear bomb dropped on Hiroshima in August 1945 and larger than the warheads found on the US Trident ICBMs.
Shortly after the detonation, which triggered an artificial magnitude 6.3 earthquake, North Korea claimed that it successfully tested a thermonuclear bomb design that can be fitted on the Hwasong-14/KN20 intercontinental-range ballistic missile (ICBM), which was first tested on July 4 and is likely capable of reaching the continental United States.
The test of a hydrogen bomb has been expected by North Korean analysts for some time and it has nonetheless triggered a nuclear war-scare in the United States and fueled repeated threats by President Trump to preemptively strike North Korean missile sites.
However, there is some question if North Korea is really the possessor of a real thermonuclear weapon.
U.S. government sources with access to the latest intelligence regarding North Korea’s nuclear weapons program have told The Diplomat that its sixth nuclear test also involved an “advanced nuclear device.” That’s a vague statement that clearly avoids the issue of a North Korean thermonuclear device.
Per the early assessment shared with The Diplomat, the device was either a boosted fission device or, as North Korea claimed in its state media, a two-stage thermonuclear bomb.
There is a big difference. A boosted fission device will have a limited yield. A true thermonuclear bomb can be easily enlarged to the multi-megaton range. The type of weapon design will also show how North Korea is focusing its nuclear R&D.
Booster fission devices – where one places fusion material in the middle of the fission warhead can produce these types of yield. The fusion that occurs releases more neutrons resulting in more “burning” of the fission fuel boosting the power. Another option is the Layered Cake design developed by the Russians. This design employs alternating layers of fission/fusion materials.
Or the North Koreans tested a true thermonuclear device; the two stage Teller-Ulam design that was designed by the US. That type of weapon can be scaled to whatever yield you want.
A true hydrogen bomb has traditionally meant a two-stage weapon – where a fission bomb is used as an X-ray source to compress and cause fusion in the “secondary.” This was the route the US took to a thermonuclear device.
A boosted fission device is basically one that has Hydrogen isotopes – Tritium and Deuterium – present in the pit/core. Under compression and nuclear bombardment as the fission reaction gets under way the isotopes fuse into Helium and free neutrons. These neutrons help “boost” the initial fission chain reaction resulting in a much more energetic fission reaction.
Or, the North Koreans could be taking a “Russian” approach with a layer cake fusion design. The Layered Cake design employs alternating layers of fission/fusion materials. It does get some of its yield from fusion and has a higher yield, but can’t be scaled up like the Teller-Ulam design.
However, does a thermonuclear device fit into North Korea’s nuclear strategy? Maybe not.
It seems that electromagnetic pulse (EMP) has a critical part in the NK nuclear strategy. The official communist party newspaper, Rodong Sinmun, published a report Monday on “the EMP might of nuclear weapons,” outlining an EMP attack produced by detonating a nuclear warhead in space.
“In general, the strong electromagnetic pulse generated from nuclear bomb explosions between 30 kilometers and 100 kilometers [18.6 miles and 62 miles] above the ground can severely impair electronic devices, electric machines, and electromagnetic grids, or destroy electric cables and safety devices,” said the article authored by Kim Songwon, dean of Kim Chaek University of Technology in Pyongyang.
“The discovery of the electromagnetic pulse as a source of high yield in the high-altitude nuclear explosion test process has given it recognition as an important strike method,” he stated.
Although it may seem that North Korea may want a thermonuclear device, if their goal is to produce a weapon that produces a large EMP (electromagnetic Pulse) they would not want to focus all their energy on hydrogen bombs because cruder fission bombs are more effective for producing EMP.
EMP is caused by gamma radiation hitting the upper atmosphere, which causes Compton currents, which cause EMP. Thermonuclear weapons, however, are less efficient at producing EMP because the first stage can pre-ionize the air which becomes conductive and hence rapidly shorts out the Compton currents generated by the fusion stage. Hence, small pure fission weapons with thin cases are far more efficient at causing EMP than most massive thermonuclear bombs.
Consequently, if the North Korea strategy is to cripple the US with an EMP, large yield thermonuclear weapons aren’t necessary. In addition, an EMP explosion in space would preclude further development of reentry vehicles.
Strategies – North Korea and America and its Allies
Kim Jung-un latest move has imparted a greater sense of urgency to the ongoing crisis. But, like the launch of a ballistic missile over Japan last week and constant threats of an EMP attack on the United States, this latest move is consistent with the North Korean cycle of defiant measures, crisis, and temporary resolution. While each successive crisis has brought the world closer to the brink of armed conflict, neither side has sought to cross the line into war. The costs and risks have been considered too high.
The current Korean crisis could lead to large-scale conflict, especially if Pyongyang carries out its threat to launch missiles close to Guam. Such an aggressive move would go beyond brinkmanship. It would probably force the Trump administration to shoot down the incoming missiles, leading to further escalation. If the North then responded with an armed strike against the U.S. and its allies, the president would have few options other than the employment of overwhelming military force. While there are no good military options, war could result from North Korea’s and U.S. miscalculation.
A more likely outcome is that the crisis will end in the same fashion that others have. The U.S. would once again call for more sanctions and more pressure on China, with the goal of persuading Kim to return to the negotiating table and accept the “denuclearization” of the Peninsula. North Korea would once again declare victory while continuing to expand its nuclear arsenal and developing ever more capable ballistic missiles.
The problem is that this solution is becoming less and less effective as North Korea becomes a more realistic nuclear threat. In July, North Korea conducted two successful tests of ICBM-class missiles. That same month, the Defense Intelligence Agency reportedly assessed that the North has successfully miniaturized a nuclear warhead that can fit in the front end of a ballistic missile. The latest nuclear test moves North Korea ever closer to what it has long sought — the ability to hold American cities hostage to Pyongyang’s blackmail demands. When the North does possess nuclear-armed ICBMs able to hold even a small number of American cities at risk, the rules of the game will change. The next crisis will be different.
Possessing the capability to target and strike U.S. cities with nuclear weapons could fundamentally alter Pyongyang’s calculations. Advocates of tough U.S. policy are asserting that, the stated policy of the Kim regime is the unification of the Peninsula, by force if necessary and that the North appears to understand the notion that, under present circumstances, it would lose an all-out war with the U.S. and its allies. They believe North Korea’s conventional forces are outmatched by the American and South Korean forces arrayed against them, which include massive forces that would flow into the theater during a conflict. They are hinting that even if Pyongyang employed large-scale chemical and biological warfare, which it is almost certainly prepared to do, the overwhelming response by the U.S., perhaps not limited to conventional retaliation, could well mean the elimination of the Kim regime.
The key for North Korea is to change what it calls the “correlation of forces” by deterring the U.S. and others from coming to the assistance of the South, especially by blocking reinforcements based in Japan, Guam, and the U.S. homeland. The means to do this is to threaten American and Japanese cities with nuclear destruction. This is the reason the North devotes enormous resources to its nuclear and missile programs — not to deter an attack by the U.S. but to deter the US from coming to the assistance of Seoul when the North moves south.
Common wisdom holds that, if North Korea launches even one nuclear weapon against the US, the result will be the complete destruction of the entire country. But from the North’s perspective – which is the one that matters most – they may believe that it is a gamble worth taking.
So how can the US manage a Korean crisis? One way would be for the U.S. to use military force to destroy North Korea’s nuclear and missile facilities now.
But picking the military option has three problems. First, while the U.S. must be prepared to respond with overwhelming force to the use of force by the North, a preemptive attack by the U.S. on a scale necessary to destroy the North’s missile and nuclear programs could result in large-scale conflict on the Korean Peninsula, with hundreds of thousands of casualties. Would U.S. allies, particularly South Korea, be willing to go along?
Second, it will be difficult to determine when to strike. The best time is only after the North Korean development and fielding of a nuclear tipped ICBM. However, intelligence assessments are usually vague and probably will never say that they are 100% sure the North Koreans have a nuclear ICBM. Internal arguments will most certainly favor delay based on the assessment that the North is not yet at the point of deploying an ICBM. But if the delay is too long, what the US is trying to prevent will occur.
And finally, there will be those who say that the US can effectively deter North Korea even if it possesses an ICBM capability, just as it deterred the Soviet Union. The problem is that we can’t assume the North Korean leadership will act as the Soviets did.
So, is there a peaceful option that the Trump administration can take that might be more effective than the strategies taken in the past?
The answer lies with THE Russians and Chinese if they could bring a proposal to resume direct U.S. and N.K negotiation.
Although Trump has made the military option a likely option, he is currently ramping up his rhetoric in order to persuade the North Koreans to take a different path. We will only know if this is successful in the long run.
PUBLICATIONS
North Korea Responds to Trump’s “Fire and Fury” Threat
By Bruce Klingner
Heritage Foundation
September 5, 2017
Pyongyang last night conducted its first test of a hydrogen (thermonuclear) bomb. The device was ten times more powerful than any of those detonated in North Korea’s five earlier atomic (fission) nuclear tests, signifying yet another surprise breakthrough in the regime’s nuclear program. This is the first nuclear test during President Trump’s tenure, and the world will be watching to see how he responds. One thing is certain: this test will further roil the already unsettled dynamics in northeast Asia. Seismic readings showed a magnitude 6.3 man-made explosion near North Korea’s known nuclear test site. According to preliminary expert analysis, that indicates an explosive yield of up to hundred kilotons. The previous high test yield was approximately sixteen to twenty kilotons—the approximate size of the Hiroshima and Nagasaki bombs.
Destabilizing Northeast Asia: The Real Impact of North Korea’s Nuclear and Missile Programs
By Anthony Cordesman
Center for Strategic and International Studies
September 5, 2017
It is all too natural for Americans to view North Korea’s nuclear and missile programs in terms of what seems to be an irrational threat to the United States: From a narrow U.S. perspective, North Korea’s action seem almost suicidal. North Korea is creating a threat to the United States that could lead the U.S. into preventive strikes against North Korea and either force it back down or trigger a conventional war that it would lose catastrophically—albeit at immense cost to South Korea. Or, if the United States does not respond with effective preventive strikes or diplomacy, actually North Korea will acquire a nuclear capability to strike at the United States which—if ever exercised—would trigger a level of massive U.S. nuclear retaliation that much—or most—of North Korea would not survive. There is, however, a different side to North Korea’s actions. The key aspects of the military balance involve South Korea, Japan, and China far more directly than the United States. North Korea is the most militarized nation in the world, and any all-out conventional war on the Korean peninsula would do immense damage to South Korea and produce massive civilian casualties.
Syrian Refugees in Turkey: Beyond Burden
By Erol Yaboke
Center for Strategic and International Studies
August 31, 2017
Dilapidated refugee camps, destroyed cities, and over-crowded inflatable boats battling the Mediterranean; these are the images that dominate coverage of displaced Syrians. After seven years of war and destruction that has caused Syria to become the largest origin of forced migrants in the world, these images of protracted dependence are sadly accurate. At the same time, they are only part of the story. Turkey, where the greatest number of displaced Syrians currently reside, has done surprisingly well creating a socially and economically cohesive society. As conversations in Turkey start to shift from short-term humanitarian support to long-term harmonization efforts, thousands of Syrian-owned businesses have already infused hundreds of millions of dollars into the Turkish economy and created tens of thousands of jobs for Syrians and Turks alike; and there’s much more from where that came.
Iran’s Concern About Kurdish Insurgency
By Michael Rubin
American Enterprise Institute
September 6, 2017
Foreign Military Studies Office
Kurds living in Iran have long been restive. Kurdish resistance to Tehran’s centralized control dates back almost a century. In the 1920s and 1930s, Reza Shah—the father of the Iranian monarch ousted in 1979—brutally crushed tribal resistance to the central government. In 1946, Kurds (including the father of Masoud Barzani, the President of the Iraqi Kurdistan Region, or IKR) briefly claimed an independent state in and around Mahabad, in northwestern Iran, but the Iranian army pacified it within a year. The 1979 Islamic Revolution compounded the disenfranchisement many Iranian Kurds felt: Not only were they ethnically different from many Persians but because Kurds are predominantly Sunni, they found themselves discriminated against twice over—ethnically and religiously—by a government which based itself on Ayatollah Khomeini’s exegesis of Shi’ite theology and political philosophy. Against this backdrop, violence in Iranian Kurdistan has never been far below the surface. The Iranian military and security forces deploy a disproportionate number of troops to keep order in the mountainous region, and the Iranian judiciary imprisons and often executes Iranian Kurds it suspects of joining Kurdish cultural or nationalist groups.
Europe’s Options on the Sidelines of the North Korea Crisis
By Janka Oertel
German Marshall Fund
August 28, 2017
For a moment, we seemed to be at the brink of nuclear escalation of the long simmering North Korea conflict. It is hard to say whether the “fire and fury” rhetoric from U.S. President Trump impressed North Korean dictator Kim Jong-un. It did, however, terrify Europeans. For decades, as Henry Kissinger put it in the Wall Street Journal, “the international community has combined condemnation with procrastination” when it comes to North Korea. The conflict is named among the top threats to international security, at least since the regime had conducted the first nuclear test in 2006. But from a European point of view, the conflict has always been far away, and many other crises have seemed much more imminent and daunting. This has changed. The last few weeks have demonstrated how immediate the risk of a military escalation with North Korea could become and how unpredictable the U.S. government currently is to European allies. But rather than allowing the conflict to drive a wedge in the transatlantic alliance, the recent developments call for more, not less transatlantic cooperation. Europe can make a meaningful contribution in various areas to support a peaceful transformation of the North Korea crisis.
Does Trump Want a Nuclear Japan?
By Walter Russell Mead
Hudson Institute
September 4, 2017
As the North Korean nuclear crisis continues to deepen, the stakes are slowly becoming clearer. This isn’t only about the threat Pyongyang poses to its neighbors or even to the U.S. mainland. Kim Jong Un is challenging the foundations of the American position in East Asia. In the process he has exposed a deep divide in American thinking, laying bare the hard choices Washington may soon be forced to make. Close observers have long understood that North Korea’s belligerence and nuclear buildup are pushing Japan toward fielding its own nuclear weapons. No nonnuclear power in the world is nearer to a nuclear capacity than Japan. Many analysts believe it would take Tokyo only months to go from deciding to nuclearize to having the weapons. In the ensuing chaos, it’s likely that South Korea and Taiwan would follow suit, with at least Taiwan receiving quiet help from Japan.
