S ource: The Diplomat
Concern about US security guarantees has prompted debate in South Korea over the possibility of redeploying US tactical nuclear weapons – or building some themselves.
Comments by influential South Koreans that their country should consider requesting the return of US nuclear weapons to their shores—or even acquire its own nuclear weapons—reflects persistent unease about how regional security developments are challenging US extended security guarantees developed during the Cold War.
In the case of South Korea, the United States pledged through a bilateral mutual defence treaty to help defend the country from an external attack, presumably from North Korea, with nuclear weapons if necessary. The deployment of sizeable US conventional forces in South Korea was aimed at making these extended security guarantees more credible.
The effectiveness of deterrence is difficult to prove, since by definition nothing happens. If a country is deterred from attacking, it is a non-event. Sceptics can plausibly argue that perhaps the presumed aggressor never intended to attack, or at least refrained from the assault for other reasons. Still, the North Korean invasion of the South was never repeated, perhaps due to US threats to retaliate—something that was lacking before June 1950.
Extended deterrence is a function of capacity, will, and perception. It requires that the guarantor has the capacity to defend another country under attack as well as the intent to do so, and this capacity-will combination must be perceived by the target as sufficiently strong that the potential aggressor decides to refrain.
In addition to deterring a potential aggressor through threats of retaliation, a deterrence pledge also involves an assurance dimension. The state receiving the guarantee must perceive it as credible given the guarantor’s capacity and will. Otherwise, it will seek to appease the potential aggressor—or balance the threat through unilateral action.
In the case of South Korea, the means of unilateral balancing under consideration has extended to include nuclear weapons. During the Cold War, the United States stationed hundreds of nuclear weapons there. At times, early South Korean governments contemplated and even started nuclear weapons programmes.
The Cold War has ended, and the Pentagon removed all US nuclear weapons from South Korea two decades ago. But the commitment to defend the country with nuclear weapons if necessary is still seen as essential to keep South Koreans from losing faith in the US willingness or capacity to defend them.
In one of his last public speeches in Asia before leaving office, then US Secretary of Defense Robert Gates acknowledged to participants at the Shangri-La Dialogue in Singapore that several developments relating to North Korea were making the East Asian strategic environment more dangerous.
First, North Korea’s indiscriminate selling of items useful for making nuclear weapons or ballistic missiles was destabilizing ‘the entire region.’ Second, the US homeland was for the first time becoming vulnerable to a direct North Korean attack. Gates related that he and President Barack Obama had told Chinese leaders several times that North Korea’s continued progress in developing long-range ballistic missiles armed with nuclear warheads was becoming a ‘direct threat to the United States.’
In addition, the risks had increased that any further North Korean provocations against South Korea would rapidly escalate into an armed confrontation between the two parties. Gates also warned that North Korea’s outrageous provocations against the South last year—sinking the Cheonan and shelling civilians on a border island—had so roused South Korean opinion that vigorous retaliation to any further provocations was much more likely. ‘And one of the worries we have dealt with over the last seven or eight months, both with our friends in the Republic of Korea and also in our dialogues with our Chinese friends and other members of the Group of Six is the danger of unpredictable escalation in the event of another provocation,’ he noted.
South Korean Defence Minister Kim Kwan Jin later told the same audience that his government had adopted a policy of ‘proactive deterrence,’ which he said would mean that ‘if there is a provocation, we will respond very strongly.’ Even before last year’s provocations led to a change in military strategy, the government of Lee Myung-bak, which had come to power in 2008, had adopted a much sterner line toward the North than its predecessors. It strictly reduced South Korean financial assistance and demanded an end to both of North Korea’s nuclear weapons programmes.
Although of less immediate concern to most South Koreans, the rising power of China has also been profoundly affecting regional security dynamics. In particular, China’s growing military power has resulted in many East Asian countries deepening their security ties with the United States and building up their defences, including by acquiring ballistic missile defences. In response, the Chinese have tightened their ties with North Korea, which, despite the headaches it causes, is a reliable buffer state. Few South Koreans consider China a military threat, but many worry about its growing economic presence in North Korea.
South Korean security experts have cited several other reasons why they believe that US extended deterrence guarantees have become less credible during the last two decades. For example, they point to the withdrawal of the US troops that had been stationed along the Korean Demilitarized Zone, where they had served as a trip-wire ensuring that any North Koreas cross-border incursions would meet a US response, to below the Han River. Furthermore, the number of US troops based in South Korea continues to decline from Cold War highs. South Koreans are also concerned that the United States might seek to negotiate a nuclear elimination deal with Pyongyang at their own country’s expense.
Finally, the Obama administration’s nuclear weapons elimination rhetoric alarms them, especially the way the April 2010 US Nuclear Posture Review modifies US conditional negative security assurances to state that: ‘The United States will not use or threaten to use nuclear weapons against non-nuclear weapons states that are party to the NPT and in compliance with their nuclear non-proliferation obligations.’
If applied as written, and Pyongyang were to eliminate its nuclear weapons and join the Nuclear Non-Proliferation Treaty, the United States wouldn’t employ nuclear weapons to defend South Korea from a North Korean attack even if chemical weapons, forward-deployed artillery, short-range missiles, and special force units were used.
Another problem is the limited scope of extended nuclear deterrence. Even if one believes that these threats of retaliation have kept the North from invading the South, extended nuclear deterrence has proven considerably less effective at preventing Pyongyang’s horizontal and vertical proliferation activities.
The former category includes the likely transfer of missiles and WMD-related items to Iran, Syria, and Burma—one of the major sources of North Korea’s export revenue. US nuclear deterrence also can’t affect the vertical proliferation taking place within the country itself, with the regime slowly and sometimes intermittently developing its nuclear weapon potential and perfecting its long-range ballistic missiles. In addition, extended nuclear deterrence is ironically most effective at dissuading a government from launching a large-scale war against a covered country, but is much less effective at averting lower-level provocations, which Pyongyang has been conducting for decades.
The United States has used various supplementary tools to address these deterrence gaps. To curb the export of WMD-related material and their means of delivery from North Korea, the George W. Bush administration launched its Proliferation Security Initiative (PSI) in 2003. The Obama administration vigorously supported the PSI, including through securing enactment of supporting UN Security Council resolutions.
The difficulty in deterring lower-level attacks—those below the level to which the United States could credibly be expected to respond with nuclear weapons—became newly evident with last year’s incidents. Even when confronting non-nuclear states, the United States has found that threats of nuclear response lack credibility when the stakes don’t warrant nuclear use. For this reason, the 1950s-era ‘Massive Retaliation’ doctrine was replaced by the Flexible Response doctrine in the 1960s, in which the United States would seek to counter revolutionary guerrilla movements with counterinsurgency warfare, massive Soviet tank armies with more sophisticated US conventional capabilities, and so forth. But the United States always declined to accept a no-first-use doctrine since Flexible Response allowed for the employment of US nuclear weapons in some conventional war scenarios, such as to prevent a Soviet tank breakthrough in Western Europe during the Cold War.
Now, though, South Korean military leaders are emphasizing in their declaratory doctrine the need for a prompt and vigorous response to future provocations. In addition, the South Korean military has stationed near the intra-Korean border dozens of US-made surface-to-surface precision-guided Army Tactical Missile Systems capable of hitting Pyongyang. The South Koreans, alone and in cooperation with the US military, have also been engaged in an expanded series of exercises during the past year. Although Chinese and Russian officials have often opposed them as provocative, the North Koreans have normally acted quietly and cautiously whenever the exercises take place.
So, what else could South Korea and the United States do to better deter North Korean aggression? One possibility would be to relax their plans to transfer operational command of joint military action on the Korean Peninsula from US Forces Korea to South Korea’s armed forces. They could also limit the scope of the combat missions that Seoul will take over from the Pentagon in the next few years. While the Americans see the move as upgrading South Korea’s status and underscoring US confidence in Seoul’s improving military capabilities, many South Koreans interpret the transfer as reflecting American eagerness to reduce its Seoul-related commitments and to reallocate US defence resources to higher security priorities.
Also, in theory at least, returning US tactical nuclear weapons to South Korea could further assure its security from northern aggression. (The United States withdrew its small battlefield nuclear weapons from South Korea in late 1991, when the two Koreas were finalizing their ‘joint declaration on the denuclearization of the Korean Peninsula’.)
The United States clearly has superior nuclear and conventional forces to those of North Korea, but many South Koreans doubt whether the US really would respond to a nuclear attack on Seoul with a retaliatory strike against Pyongyang, especially if the North might respond by attacking US forces in Japan, or even striking the US homeland directly, with nuclear-armed ballistic missiles. If the US nukes were already in South Korea, however, the North Korean leadership might be deterred since the weapons would be more visible and could more plausibly be fired, perhaps inadvertently, following an attack.
The North Koreans would be even more credibly deterred if South Korea possessed its own nuclear weapons since the Seoul government and military would be even more inclined to retaliate to a nuclear attack against its population or territory. Some South Koreans have become frustrated about the failure of the Six-Party Talks and other efforts to roll back North Korea’s nuclear programme, and see having their own nuclear weapons as ‘an equalizer’ to allow Seoul to negotiate with Pyongyang about Korean denuclearization from a position of equality and without having to adopt an aggressive conventional pre-emption doctrine against the North.
But regardless of how decision makers in Seoul see it, South Korea’s neighbours wouldn’t welcome a return of US nuclear weapons to the Peninsula—or South Korea’s acquisition of an independent nuclear deterrent. Beijing would be most likely to oppose these developments, since any nuclear weapons that could attack targets in North Korea would most likely be able to devastate targets in China as well.
And there’s one more reason why South Korea would meet opposition to doing so even from its ally the United States—the Obama administration is committed to decreasing the role of nuclear weapons in the world. Supporting the development of nuclear weapons in South Korea hardly seems consistent with this goal.