In August, the North Korean ballistic missile test submarine, Gorae, successfully fired a missile—designated by the North Koreans as Polaris-1 but by the United States as KN-11—to a range of 500 km. Because it followed a lofted trajectory, the missile did not fly to its maximum potential range, which probably is between 1,000 and 1,200 km (approximately 540 to 650 nautical miles). The Gorae is a single-tube submarine used mainly for tests, but the Sinpo shipyard is being upgraded, and an apparent component of a considerably larger submarine has been spotted there. A submarine with up to four launch tubes reportedly is planned for completion in 2017. Given the usual time required for research, development, test, and evaluation, the North Koreans could have an operational ballistic missile submarine by 2020, barring significant problems.
The KN-11 missile uses solid fuel, which the North Koreans have not previously employed in a large ballistic missile. This raises an interesting question: where did the technology come from? The most plausible source is Iran, which has a large and active ballistic missile program as well as close ties to North Korea. Presumably Pyongyang is offering Tehran something in return, which suggests possibly a nuclear weapon design and perhaps also the supply of nuclear material. If that is the case, Iran could be closer to having a nuclear weapon than is generally thought. Moreover, it is difficult to say how close the Iranians are to a nuclear weapon simply by monitoring events in Iran. Sanctions blocking ships going from North Korea to Iran are imperfect, because the technology and equipment involved could easily be transported by air—and no one is shooting down North Korean cargo planes.
In a related development, on 9 September North Korea conducted its fifth nuclear test, with an estimated yield of 10 kilotons. Pyongyang claimed this warhead was small enough to be mounted on a ballistic missile. There has been considerable speculation about North Korea’s capacity to miniaturize nuclear weapons, but the latest test announcement included claims that the test proved North Korea could now build nuclear weapons in any desired size, and also that the test had been thermonuclear. Typically, the latter claim would mean a hydrogen bomb with a yield of hundreds of kilotons or megatons—or, in Cold War terms, a city-buster. It seems more likely that North Korea’s claim referred to a technique for increasing the inherent power offered by a particular weight of nuclear material. That assumes, of course, that the North Korean statement is more than bluster.
In addition to the nuclear detonation and the submerged ballistic missile launch test, the North Koreans fired four land-based ballistic missiles in quick succession to a range of 1,000 km, all of them hitting in roughly the same place. Some commentators saw this as a demonstration that the North Koreans could saturate missile defense systems. South Korea (ROK) is considering buying the U.S. Terminal High Altitude Area Defense (THAAD) ballistic missile defense (BMD) system. The ROK’s Aegis destroyers presumably can be modified to launch the SM-3 anti-ballistic missile interceptor. Beijing is pressuring Seoul to abandon the THAAD program on the grounds it is destablilizing. What China actually means is that in addition to reducing the threat presented by North Korean missiles, THAAD devalues the Chinese strategic threat to South Korea.
All of this is somewhat symbolic. Seoul, in which much of the South Korean population and economy is concentrated, is so close to the North Korean border that the North would not need long-range missiles to hit it. A few missiles with kiloton warheads could do enormous damage, but they probably could not destroy the large, sprawling, modern city. Whatever was left of the South Korean government after such an attack could and would fight back.
When the new North Korean threat was publicized, the South Korean government told its lawmakers it had the capacity to wipe out Pyongyang. It is not clear how that was to be accomplished; the statements may have been intended to head off demands that South Korea immediately develop nuclear weapons of its own. The United States convinced the South’s government to terminate an earlier covert nuclear program, arguing that the U.S. nuclear umbrella was enough. Now the South Koreans are demanding the United States demonstrate its seriousness by again stationing nuclear weapons on South Korean territory. The U.S. position is that its strategic systems, such as bombers and strategic submarines, are sufficient to threaten North Korea, so there is no point in deploying short-range nuclear weapons on the peninsula.
Short-range nuclear weapons formerly were stationed in Europe and Korea but were withdrawn at the end of the Cold War. It is not clear how many such weapons are still intact. Probably the only short-range nuclear system that could easily be deployed to South Korea would be bombs dropped from fighter-bombers, whose airfields surely would be among the first targets of a North Korean strike.
The chairman of the South Korean Joint Chiefs of Staff called for development of a South Korean nuclear attack submarine (SSN) as the natural counter to North Korea’s strategic ballistic submarine. In his view, an ROK SSN could lie off the North Korean submarine base, ready to intercept or trail any North Korean strategic submarine that emerged, and to destroy it if it was preparing to fire missiles. The Chinese may envisage a similar option, as they already have nuclear submarines.
Kim Jong-Un might not be particularly concerned by a threat to erase Pyongyang, given his demonstrated indifference to the fates of ordinary North Koreans. He and his father have been responsible for major famines, and they never have been willing to sacrifice political power or their nuclear program in return for aid of any kind.
South Korean lawmakers were told of a second and perhaps more plausible deterrent—that the ROK military had the ability to kill Kim Jong-Un, presumably by a precision air attack. That may or may not impress Kim Jong-Un. Like other dictators, he is well aware that enemies seek to kill him. Successive executions of North Korean elites presumably have been intended to deter those seeking his overthrow. Kim’s defenses doubtless include being difficult to track, just as at the outset of Operation Iraqi Freedom Saddam Hussein proved quite capable of evading U.S. attempts to target him. It is not clear, then, just how seriously Kim takes South Korean claims that he is continuously tracked and therefore vulnerable. If that claim is credible (to Kim), then the South Koreans have a real deterrent.
How would the advent of a North Korean missile submarine affect the situation? Current and projected South Korean defenses are intended to cover the corridor through which North Korean missiles have to fly. In theory the South could extend its ballistic missile defenses to cover the seaward approaches against sub-launched ballistic missiles, but at great cost. The South also might invest in long-range acoustic sensors, like those NATO deployed during the Cold War. That option, too, would be expensive, and the seas around Korea are reportedly poorly adapted to such sensors.
North Korea’s actions affect other countries in the area. Like China, North Korea uses Japanese World War II atrocities as a unifying theme against Tokyo. The increasingly impressive North Korean tests have made Japan more aware of its own vulnerability. At the very least, Japan is likely to invest more in ballistic missile defense, particularly SM-3 and Aegis. More important for East Asia as a whole, North Korea’s nuclear weapons and ballistic missiles stir Japanese sentiments that they need their own nuclear weapons. Japan has a substantial stockpile of nuclear material from its large civilian nuclear power program and sophisticated military technology. If that nation chose to “go nuclear,” it probably could do so quickly, on a large scale, and with far more powerful weapons than the North Koreans have tested.
China likely is unhappy to have a nuclear power on its border. It is, however, unwilling to significantly pressure Pyongyang and risk a North Korean economic and political collapse, which could create a humanitarian crisis on its border and potentially lead to a unified peninsula under ROK leadership. The Chinese have been able to apply limited pressure to North Korea because they are the single vital source of much of what the North needs, including much of its food. The more effectively North Korea arms itself, however, the less leverage China has. The open question is whether Kim Jong-Un really cares about damage to his country and his people. If he is willing to accept considerable damage, even a small nuclear arsenal may give him valuable leverage against his enemies and China. Having long played this game against the United States, the Chinese well understand the strength of Kim’s position in this game of bluff. His weapons do not have to be used to exert leverage.
The growth of North Korea’s nuclear threat opens up the sobering possibility that deterrence—maintaining military power for the purpose of discouraging attacks—may not always work. The same also may apply to a future nuclear-armed Iran. Whether deterrence works depends on how much our threat impresses the leadership in Pyongyang and Tehran. Exactly what threats would deter the Soviet leadership was an active question throughout the Cold War. Mutually Assured Destruction was the overarching deterrent policy during the 50 year struggle between the United States and the Soviet Union. Fortunately, the Cold War never reached the level at which either side risked retaliation. It is not clear that similar optimism can be applied to the developing situation in East Asia. We may not understand Kim Jong-Un well enough to know what, if anything, would deter him.
Dr. Friedman is the author of The Naval Institute Guide to World Naval Weapon Systems, Fifth Edition, and Network-centric Warfare: How Navies Learned to Fight Smarter through Three World Wars, available from the Naval Institute Press at www.usni.org.