James Martin Center for Nonproliferation Studies
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North Korea Special Collection

Phillip C. Saunders[1]

As the crisis over North Korea's nuclear weapons program continues, an obvious question is whether the United States might use military force to resolve the crisis. This report explores some of the tactical issues that would be involved in military strikes against North Korean nuclear facilities and explains why an anonymous senior Bush administration official concluded that although the United States has military options, "we don't have good ones." [2]

Three key issues would be involved in successful military strikes against North Korean nuclear facilities:

1) locating all facilities and fissile material stocks that could be used in a nuclear weapons program;
2) possessing the capability to destroy these targets; and
3) preventing North Korea from retaliating with artillery fire, missile strikes, chemical or biological weapons use, escalation to a full-scale conventional war, or nuclear weapons.

Each of these issues presents considerable difficulties in the North Korea context, but the problem of preventing or limiting North Korean retaliation is the hardest. In addition to the tactical issues addressed here, the potential political consequences in terms of U.S. relations with South Korea, Japan, Russia, and China make military strikes a very unattractive option compared to a diplomatic resolution of the crisis.

Locating North Korean Nuclear Facilities

A number of the facilities involved in North Korea's nuclear program have already been identified and precisely located.[3] These include the nuclear reactors, fuel fabrication facilities, and reprocessing facilities that constitute the critical parts of the North Korean nuclear infrastructure for producing and reprocessing plutonium for possible use in nuclear weapons. North Korea is unlikely to have secret nuclear reactors, but it could have secret facilities that could reprocess spent fuel into plutonium. Any such covert reprocessing facilities would likely be on a relatively small scale, and could be hidden underground or in caves for secrecy and increased protection against attack.

In October 2002, U.S. officials accused North Korea of having a covert uranium enrichment program in violation of the Agreed Framework. (Plutonium and uranium enrichment are two separate paths to producing fissile material for nuclear weapons.) North Korean officials reportedly admitted having a covert nuclear weapons program. No North Korean uranium enrichment facilities have been located, although three suspect sites have been identified.[4] Uranium enrichment can be conducted in relatively small facilities, including underground facilities that are difficult to attack. It is not clear how far North Korean uranium enrichment efforts have progressed, but it is possible that unknown secret production facilities exist.

In addition to these facilities, any North Korean nuclear weapons or stocks of secretly reprocessed plutonium would be critical targets. U.S. intelligence officials believe that North Korea has enough plutonium to build one or two nuclear weapons and has probably already constructed them. However the precise location of these weapons (or the secretly reprocessed plutonium) is unknown. It is logical to assume that the weapons or plutonium are probably not located in declared North Korean nuclear facilities and that North Korea has sought to make them as secure as possible from outside attack.

Possessing the Capability to Destroy North Korean Nuclear Facilities

North Korea has reasonably capable air defenses, including Mig-29 fighters, SA-2 and SA-5 surface-to-air missiles, and large quantities of anti-aircraft artillery (AAA). Nevertheless, North Korean nuclear facilities located in the open would be highly vulnerable to attack by cruise missiles and by American stealth fighters or bombers armed with precision-guided munitions. Use of U.S. bases in South Korea would make an attack easier, but if necessary an attack could be launched using sea-based missiles and bombers based on U.S. territory. North Korea's reactors, fuel fabrication facilities, and the reprocessing facilities necessary for producing plutonium for nuclear weapons would be relatively easy to destroy.

Nuclear facilities that are unknown or that have not been located obviously cannot be attacked. North Korean efforts to use underground and buried facilities to provide protection against attack present an additional difficulty. The U.S. military has tried to develop earth-penetrating conventional weapons to attack hardened or deeply-buried targets, but these weapons might not be effective against some targets. The Pentagon's 2002 Nuclear Posture Review reportedly recommends studying ways to adapt existing nuclear weapons or developing new earth-penetrating nuclear weapons to attack these targets.[5] North Korea makes extensive use of tunneling and hardening to protect its military facilities. Any secret nuclear facilities or storage sites for nuclear weapons or plutonium stocks are likely to be protected in this manner, making it difficult to attack them with conventional weapons even if their precise locations were discovered.

Strikes against North Korean nuclear facilities might also spread radioactive material widely in North Korea, South Korea, and even in Japan and China. Although classified U.S. military studies reportedly suggest the radiation could be contained to limited areas, the possibility of extensive contamination and civilian casualties would be an additional concern.[6]

Preventing North Korean Retaliation

The biggest military concern in striking North Korean nuclear facilities is the threat of North Korean counter-attacks. Seoul, the South Korean capitol, lies within range of North Korean long-range artillery. Five hundred 170mm Koksan guns and 200 multiple-launch rocket systems could hit Seoul with artillery shells and chemical weapons, causing panic and massive civilian casualties. North Korea has between 500 and 600 Scud missiles that could strike targets throughout South Korea with conventional warheads or chemical weapons. North Korea could hit Japan with its 100 No-dong missiles.[7] Seventy percent of North Korean army ground units are located within 100 miles of the demilitarized zone separating North and South Korea, positioned to undertake offensive ground operations. These units could fire up to 500,000 artillery rounds per hour against South Korean defenses for several hours.[8] Finally, if North Korea does have one or two deliverable nuclear weapons, nuclear retaliation (or nuclear threats) would also be available to North Korea leaders.

Even if U.S. strikes on North Korea nuclear facilities are successful, North Korea would still have the capability to inflict massive damage against South Korea and the 37,000 U.S. troops based there. Retaliation might be gradual, or North Korea might resort to large-scale strikes quickly. Efforts to invade the South are less likely, but cannot be ruled out entirely (especially if U.S. military forces are preoccupied in the Persian Gulf). The decision about how to respond would be up to North Korean leaders, who would have a range of military options and the ability to escalate the conflict over time. Although the United States would likely win an all-out war, the damage to South Korea would be tremendous and U.S. forces would sustain large casualties. One U.S. military estimate suggested that U.S. and South Korean military forces might suffer 300,000-500,000 casualties within the first 90 days of fighting, in addition to hundreds of thousands of civilian casualties.[9]

Given these possible military responses, attacks against North Korean nuclear facilities would need to be accompanied by measures to prevent or limit retaliation, such as efforts to degrade North Korean military capabilities, defend against counter-attacks, and deter military responses.

Because North Korea has a wide range of military means (including artillery, missiles, and ground-force operations) that can inflict significant damage on the South, pre-emptive strikes could not destroy all of North Korea's weapons before they could be used. Pre-emptive strikes against North Korean artillery and missiles would require South Korean cooperation and the deployment of additional U.S. aircraft, reconnaissance assets, and artillery. Counter-battery artillery fire and air strikes could be used to target North Korea artillery, but would be unable to prevent North Korea from doing considerable damage to Seoul. The number and mobility of North Korea artillery pieces and ballistic missile forces make them particularly tough targets. Many North Korean artillery pieces are protected in caves and would be difficult to destroy; North Korean missiles are mounted on mobile launchers that are hard to locate and strike. As mentioned previously, any North Korean nuclear weapons would likely be hidden in hardened underground facilities. Because pre-emptive strikes against North Korean artillery and missiles would require striking targets throughout the country, they would quickly escalate the conflict into a wider war. For this reason, pre-emptive strikes would be unlikely to accompany surgical strikes against North Korean nuclear facilities, but would be held in reserve in case North Korea began to retaliate with missile and artillery attacks.

Efforts to reinforce U.S. and South Korean defenses would provide additional protection against a North Korean ground attack, some protection against North Korean missile attacks, and little or no protection against North Korean artillery. The U.S. Army has already deployed some Patriot missile defense batteries in South Korea to protect U.S. troops and airbases. The Patriot would provide some protection against North Korean missile attacks, but it cannot provide wide-area coverage and is unlikely to destroy all incoming North Korean missiles in a concerted attack. North Korean missiles armed with chemical or biological warheads might be able to do considerable damage even if they are successfully intercepted. If Patriot systems were deployed to protect Japan, they would provide only very limited point defense against North Korean No-dong missiles. The only protection against North Korean artillery fire would be to try to destroy individual artillery pieces as quickly as possible.

Because efforts to degrade North Korean military capabilities and defend against attacks could not prevent North Korea from inflicting major damage on South Korean and Japanese targets, the United States would likely focus on deterring Pyongyang from counter-attacking by threatening to escalate the conflict to an unacceptable level of violence. This might include a statement of limited U.S. military objectives in the initial attack on North Korean nuclear facilities, threats to use devastating conventional attacks in response to a major North Korean counter-attack, military deployments to make the threat of conventional retaliation more credible, and explicit threats to use nuclear weapons in response to North Korean retaliation using chemical, biological, or nuclear weapons. Although it would not be necessary militarily, deployment of nuclear weapons to South Korea could be used to signal U.S. willingness to escalate the conflict to the nuclear level.

This would be a high-risk strategy that would seek to use the threat of escalation to minimize the North Korean military response. If deterrence failed, the initiative would be in North Korean hands, and the military situation might escalate rapidly toward a major conventional war and the possible use of weapons of mass destruction. Deployments of U.S. forces in the Persian Gulf would reduce potential U.S. surveillance and strike capabilities on the Korean peninsula and limit the number of troops that could be deployed to Korea to halt a possible North Korean ground offensive. One consequence would be to reduce the threshold for the use of nuclear weapons if the conventional war began going badly for U.S. and South Korean forces.

From a political point of view, a U.S. pre-emptive strike would mean that the United States would be blamed for starting the military conflict. If North Korea employed its military assets skillfully, attacks and threats could be used to divide the United States politically from Japan and South Korea (and perhaps make a long-term U.S. military presence in both countries untenable). For example, North Korea could respond by targeting U.S. air bases in South Korea and Japan in order to highlight the point that it is the presence of U.S. forces that makes those countries a target. Although North Korean leaders would be concerned about the danger of an all-out war that could result in the destruction of both their regime and their country, they might calculate that South Korean and Japanese leaders are even more averse to a major war. North Korea could use limited counter-attacks to inflict damage and ratchet up the pressure on U.S. allies to reach a compromise that ended the fighting. North Korea's ability to escalate the conflict into a large-scale ground war that South Korea and the United States do not want would be a powerful negotiating chip.

Conclusion

From the foregoing analysis, it is easy to see why available military options look unattractive to U.S. planners. U.S. military strikes could probably destroy North Korea's future ability to produce and reprocess plutonium for use in nuclear weapons, preventing North Korea from moving from the one or two nuclear weapons that might be available now to the six to eight weapons that would be available if the spent fuel rods stored in Yongbyon were reprocessed to produce plutonium. These strikes could potentially remove North Korea's ability to produce large quantities of plutonium for the next several years. However an attack is highly unlikely to destroy any existing North Korean nuclear weapons capability. Because the facilities involved in North Korea's uranium enrichment program have not been located (and are likely in hardened or underground sites that are difficult to destroy), military strikes would be unable to prevent North Korea from producing fissile material via uranium enrichment. The available information is insufficient to determine how quickly North Korea might be able to produce additional nuclear weapons using uranium enrichment. However one source estimates that North Korea might be able to produce up to 100 kg of highly-enriched uranium per year (enough for about six nuclear weapons) within one to three years.[10]

The biggest problem with military options is the difficulty of preventing North Korean military retaliation. Defenses could not protect the South Korean population from North Korean artillery and missile strikes, while U.S. efforts to attack these weapons would escalate the conflict without removing North Korea's retaliatory capability. The United States would be forced to rely upon deterrence--possibly reinforced with explicit nuclear threats--to prevent or limit North Korean counter-attacks. North Korea would have the initiative and the ability to calibrate its response to maximize U.S. political and military problems. This might include threats or the actual use of chemical, biological, or nuclear weapons. The most likely result would be North Korean conventional counter-attacks combined with threats to escalate toward a full-scale ground war and the possible use of weapons of mass destruction. If deterrence failed to prevent North Korean counter-attacks, the United States would be faced with a very unappealing military situation, especially at a time when many U.S. forces are deployed in the Persian Gulf.

The political consequences might be even more significant. South Korea and Japan strongly oppose military attacks against North Korean nuclear facilities, largely due to their vulnerability to North Korean retaliatory strikes. Their alliances with the United States are predicated on the belief that the presence of U.S. forces on their territory enhances their security. U.S. military actions that resulted in North Korean counter-attacks against their territory could destroy support for an alliance with the United States and end U.S. access to bases in South Korea and Japan. Military attacks might also fundamentally change the nature of U.S. relations with China and Russia, who strongly oppose resolving the nuclear crisis through military means. There is even some possibility of direct military conflict with China (which still has a security treaty with North Korea). More broadly, a U.S. pre-emptive strike against North Korean nuclear facilities would arguably violate international law and would convey the message that the United States can use nuclear threats to attack sovereign states with impunity. This would reinforce concerns many countries have about a growing trend towards unilateralism in American foreign policy. The result might only undermine the nuclear nonproliferation regime, but also damage the foundations of the current international order.

Given the high risks and limited ability of military strikes to destroy North Korean nuclear capabilities, it is easy to see why Bush administration officials, like the Clinton administration officials before them, have decided that military means are an unattractive way to resolve the North Korean nuclear crisis.

[1] Dr. Phillip C. Saunders is the Director of the East Asia Nonproliferation Program, Center for Nonproliferation Studies, Monterey Institute of International Studies.
[2] David E. Sanger, "U.S. Eases Threat On Nuclear Arms For North Korea," New York Times, December 30, 2002, p. 1.
[3] For an overview of the North Korean nuclear program, see Dan Pinkston and Stephanie Lieggi, "North Korea's Nuclear Program: Key Concerns," Center for Nonproliferation Studies, http://cns.miis.edu/research/korea/keycon.htm. For details on known and suspected facilities, see the North Korea Nuclear Profile prepared by the Center for Nonproliferation Studies, http://www.nti.org/db/profiles/dprk/nuc/nuc_overview.html.
[4] Possible locations for North Korea's highly-enriched uranium program include a uranium milling facility under Mt. Ch'onma in Taegwan-kun, North P'yong'an Province, and other suspected underground facilities at "Ha'gap," Pakch'on-kun, and T'aech'on-kun. For details, see the North Korea Nuclear Profile prepared by the Center for Nonproliferation Studies, http://www.nti.org/db/profiles/dprk/nuc/nuc_overview.html#heu.
[5] See Michael R. Gordon, "U.S. Nuclear Plan Sees New Targets and New Weapons," New York Times, March 10, 2002, p. A1 and J.D. Crouch, "Special Briefing on the Nuclear Posture Review," January 9, 2002, http://www.defenselink.mil/news/Jan2002/t01092002_t0109npr.html.
[6] See Leon V. Sigal, Disarming Strangers: Nuclear Diplomacy with North Korea (Princeton, N.J.: Princeton University Press, 1998), p. 76.
[7] Vernon Loeb and Peter Slevin, "Overcoming North Korea's 'Tyranny of Proximity'," Washington Post, January 20, 2003, p. A16; and U.S. Secretary of Defense, "2000 Report to Congress: Military Situation on the Korean Peninsula," September 12, 2000.
[8] General Thomas A. Schwartz, Statement before the Senate Armed Services Committee, March 7, 2000.
[9] R. Jeffrey Smith, "North Korea Deal Urged by State Dept.," Washington Post, November 15, 1993, p. A15.
[10] See "Beyond the Agreed Framework: The DPRK's Projected Atomic Bomb Making Capabilities, 2002-09," An Analysis of The Nonproliferation Policy Education Center (NPEC), December 3, 2002, http://www.npec-web.org/projects/fissile2.htm.

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