第二次朝鮮戦争を準備する：エスカレートする第二次朝鮮戦争
英王立統合防衛・安全保障研究所（RUSI）のマルコム・チャルマース（Malcolm Chalmers）教授の書いた 韓国での戦争を準備する（Preparing for War in Korea）から
III. エスカレートする第二次朝鮮戦争
●アメリカが北朝鮮に攻撃にした場合、中国がどのように反応するかは予想するのが難しい。
●中国の同盟国の一つが自国の国境付近で崩壊するのは、中国指導部に対する侮辱と映るだろう。
●韓国には100万名以上の中国人が住んでいる。そのうち10万人がソウルに住むといわれている。
●中国はすでに北朝鮮の国境付近で軍事力の強化を図っている、ありうる戦争準備のためだ。
●中国の軍事介入は、アメリカ軍が中国国境に近づせないようにし、寧辺核施設と豊渓里核実験場を含めるバッファゾーンを占領するだろう。現在の体制の一部を保護するかもしれない。その時は、アメリカ軍と韓国軍との対立の可能性が高くなる。
●中国との対立を避けるためにアメリカは中国の要求を受け入れることがアメリカの利益であると考えるだろう。中国はアメリカと協力する引き替えに、新しく統一した朝鮮からアメリカ軍の撤退を要求するだろう。
●中国は、北朝鮮の経済政策や政治的転覆をはかり、北朝鮮の状況を複雑化させることができる。
●第二次朝鮮戦争の戦後処理と長期政策についてアメリカと中国が同意するなら、両超大国の長いより良い関係を築きうる。したがってこの可能性が高い。
●第二次朝鮮戦争がもしも起こるとすれば、その目的は朝鮮半島の非核化である。
●アメリカは通常兵器を使用し、北の核兵器のありかを発見しそれを破壊するだろう。アメリカは報復のためでも核兵器を使用しないだろう。
●アメリカ軍の侵攻の場合、北朝鮮は核兵器を使う誘惑を受けるだろう。隣国の一つにまず一つ核を使い、より広範囲の核攻撃で脅しながら、停戦という政治的譲歩を引き出そうとするだろう。
●もしもこの脅迫による譲歩があったとすると、弱小国は強大国に対して、核兵器が政治的に利用できると理解し、核兵器はより拡散する危険が増大する。
●北朝鮮の緊張にもかかわらず、中国と日本とともに韓国は経済的に発展してきた。
●朝鮮半島での戦争はこの経済的成功に大きな打撃を与えるだろう。多くの製品とサービスの生産はストップするだろう。空路と海路の交通も停止するかもしれない。朝鮮半島と日本と中国の地域では、保険と移動の費用が高価になる。
●中国がアメリカと軍事的に対立する可能性は低いが、経済的に影響を受ける。投資は減少し、延期され、別の場所に逃避させられるだろう。
●もしも中国が北朝鮮を援助するようなことがあれば、アメリカは北朝鮮への経済制裁を中国にも拡大させるかもしれない。そうなれば中国もアメリカに経済的に報復する（アメリカの国債市場や中国へのアメリカ企業の投資）可能性がある。
●戦争の費用と戦後処理に莫大なコストがかかる。戦後朝鮮半島の統一後、北に多くの投資があるだろう。しかし統一のための費用は韓国が支払うことになるだろう。
III. The Shadow of Escalation
China's Response
CHINA'S REACTION TO a US preventive strike on North Korea is hard to predict. The collapse of one of its few allies followed by the advance of US troops towards its own border would risk humiliating its leadership. Moreover, there are an estimated 1 million Chinese citizens living in South Korea, of whom around 100,000 are reported to live in the Seoul area. All would potentially be at risk from North Korean retaliation and the turmoil that would follow.1
China is also concerned at the prospect of large numbers of refugees fleeing across its border, creating instability in neighbouring areas of its territory.2 There are already indications that China is reinforcing its military presence near its border with North Korea in preparation for a possible war.3 A retired People's Liberation Army general has suggested that China would need to establish refugee camps on its territory in the event of conflict.4
Beyond such defensive measures, some form of Chinese military intervention would be quite likely, both to ensure that US (or allied) forces did not reach its own border and to maximise its leverage in shaping the political order that emerges in the wake of occupation. It might, for example, seek to occupy a buffer zone in adjoining areas of North Korea, including the Yongbyon nuclear complex and the Punggye-ri nuclear test site, both of which are within 100 km of the Chinese border.5 If it were also to use such an intervention to protect the regime, or at least some elements of it, the chances of confrontation with advancing US and South Korean troops would be high.
In order to avoid such an escalation, it would be in the interests of both the US and South Korea to reassure China that they were prepared to take steps to meet its concerns. China might insist on the removal of all US troops from the territory of a newly unified Korea in return for its own cooperation. In the absence of substantial reassurances of this sort, and even if it were not prepared to intervene militarily, China would have many other ways to complicate North
Korean stabilisation, for example through economic pressure and political subversion. On the other hand, if the US and China were to agree a longer-term political settlement for post-war Korea, endorsed by the UN Security Council, it might go a long way towards improving the wider relationship between the two superpowers. The stakes would therefore be very high indeed.
Nuclear Consequences
If a new Korean war were to take place, one of its central purposes would be to ensure the denuclearisation of the Korean Peninsula, and thereby reduce the global total of nuclear-armed states from nine to eight. Its course and outcome would be followed closely by other states that might be considering the acquisition of a nuclear capability.
Trump has reportedly asked for advice on how to certify that Iran is no longer compliant with the nuclear deal enshrined in UN Security Council Resolution 2231.6 If the nuclear deal were to break down as a result, and Iran were to revive its efforts to acquire nuclear weapons, past debates on US and Israeli military options in relation to Iran could soon return to the policy debate. It is hard to imagine that the US would want to be involved in major conflicts against significant state adversaries in two regions at once. But concerns over a possible US attack on Iran could increase if Trump had demonstrated his willingness to take action over North Korea.
The consequences for global nuclear regimes would reach even further if nuclear weapons were actually used. There has been some talk that the US would consider the use of its own nuclear weapons in retaliation for a North Korean nuclear attack.7 However, such a step would be both operationally unnecessary and morally unacceptable. Once their locations are known, the vast majority of militarily relevant targets in North Korea can be destroyed using conventional capabilities. Even where bunkers are located below the depth that conventional munitions can reach, the extent of likely US air superiority is such that alternative conventional means could be deployed to seal such facilities until ground troops can reach them.
Using US nuclear weapons solely as a means of revenge would be even less morally acceptable and would inflict lasting damage on America's international reputation. Inflicting massive suffering on the North Korean people in response to a programme for which they had no responsibility, and without any operational rationale for doing so, would be blatantly contrary to international law on the need for proportionality (in relation to the objectives sought) and discrimination (in relation to non-combatants) in armed conflict. If the president were to order such a step, the defense secretary and all those in the chain of command would be obliged to carry out his order.8 It is hard to imagine, however, that Trump would be prepared to order such a step.
It would be vital to the cause of global nuclear order that the first use of nuclear weapons since 1945 (in this case, by North Korea) was seen to be entirely counterproductive. In the event of an invasion, the North Korean government could be tempted to use a nuclear weapon against one of its neighbours and then demand political concessions, such as a ceasefire, as the price for not repeating the strike on a larger scale. Yet if, as a result, nuclear weapons were seen as having political utility for a weak state confronting a major power, the consequences for wider nuclear proliferation could be very serious.
Economic Uncertainties
Despite continuing tensions, the Korean Peninsula – and indeed northeast Asia as a whole – has been at peace since the 1950s. Partly as a consequence, it has become one of the most economically dynamic regions in the world, with two of the world's three largest economies measured by total GDP (China and Japan). The South Korean economy alone was estimated to be 10% larger than Russia's in 2016.9
A major war on the Korean Peninsula would have profound consequences for this economic success. First, the short- to medium-term effect on South Korea itself would be substantial. If a war involved attacks on Seoul and other urban centres, production of many goods and services would stop. Global companies, including Korea-based Samsung, have come to rely on South Korean suppliers for key, often hi-tech, components, and would have to incur substantial costs in finding alternative sources. Air and maritime traffic would be disrupted, and perhaps halted, with insurance and shipping costs rising sharply for the region.
While the chances of China getting embroiled in a major conflict with the US appear to be quite low, a war could still have a dampening longer-term effect on its economy, with increased political uncertainty in the wake of a major threat to China's interests in its neighbourhood. Investors would become increasingly wary of over-exposure to the region, postponing decisions or moving capital elsewhere. A new Korean war might also deepen wider US–China tensions, thereby increasing the chances of new economic sanctions, for example in relation to trade or investment. If China were to provide support to a North Korean insurgency, some in the US might call for strategic sanctions (of the sort now being applied to Russia) to be extended to China. The Chinese government also has a range of retaliatory measures which it could consider – for example in relation to the US bond market or US corporate investors in China.
Not least, there would be substantial direct costs as a result of the war and its aftermath. Substantial refugee flows would be likely, especially if a conflict were to be protracted. Post-war unification would lead to massive demands for new investment in the North. It would be in the interests of the wider international community – the US, China, Japan, Europe, the UK, brought together by the UN and international financial institutions – to contribute to making this a success. But the largest share of the financial cost of unification, and most of the human energy required, would fall to South Korea, which would also be faced with the costs of repairing the damage to its own territory from the war. There might over time be economic advantages from having access to a large additional workforce, especially given South Korea's rapidly ageing population, but such potential gains, which would in any case be dependent on political stabilisation, would pale compared to the likely costs of reconstruction and investment.
1. Franz-Stefan Gady, ‘Would North Korea Risk the Death of 10,000 Chinese Citizens to Capture Seoul?', The Diplomat, 4 May 2017.
2. Eleanor Albert, ‘The China–North Korea Relationship', Council on Foreign Relations, 5 July 2017.
3. Adam Mount, ‘How China Sees North Korea', The Atlantic, 29 August 2017.
4. James Griffiths and Serenitie Wang, ‘Is China Reinforcing its Border with North Korea?', CNN, updated 26 July 2017.
5. Frank Aum, ‘North Korea and the Need for A US-ROK-PRC Dialogue', US Institute of Peace, August 2017, p. 4.
6. Gardiner Harris and David E Sanger, ‘Trump May Make Congress Decide Future of Iran Nuclear Deal', New York Times, 7 September 2017.
7. Fred Kaplan, ‘Don't Panic about North Korea', Slate, 5 September 2017; Ralph Peters, ‘Here's How to Take out North Korea's Nukes', New York Post, 9 August 2017.
8. For further discussion, see Sarah Grant and Jack Goldsmith, ‘What if President Trump Orders Secretary of Defense Mattis to Do Something Deeply Unwise?', Lawfare, 22 August 2017. The provisions of the 25th Amendment to the US Constitution, which provide for the removal of the president when deemed unfit for office, might be invoked in such circumstances, but would require the agreement of two-thirds of the members of both houses of Congress. See Joel Goldstein, ‘Trump Opponents Have Rediscovered the 25th Amendment. Here is What You Should Know about it', Washington Post, 7 June 2017.
9. International Monetary Fund, ‘World Economic Outlook Database', April 2017.
英王立統合防衛・安全保障研究所（RUSI）のマルコム・チャルマース（Malcolm Chalmers）教授の書いた 韓国での戦争を準備する（Preparing for War in Korea）から
III. エスカレートする第二次朝鮮戦争
●アメリカが北朝鮮に攻撃にした場合、中国がどのように反応するかは予想するのが難しい。
●中国の同盟国の一つが自国の国境付近で崩壊するのは、中国指導部に対する侮辱と映るだろう。
●韓国には100万名以上の中国人が住んでいる。そのうち10万人がソウルに住むといわれている。
●中国はすでに北朝鮮の国境付近で軍事力の強化を図っている、ありうる戦争準備のためだ。
●中国の軍事介入は、アメリカ軍が中国国境に近づせないようにし、寧辺核施設と豊渓里核実験場を含めるバッファゾーンを占領するだろう。現在の体制の一部を保護するかもしれない。その時は、アメリカ軍と韓国軍との対立の可能性が高くなる。
●中国との対立を避けるためにアメリカは中国の要求を受け入れることがアメリカの利益であると考えるだろう。中国はアメリカと協力する引き替えに、新しく統一した朝鮮からアメリカ軍の撤退を要求するだろう。
●中国は、北朝鮮の経済政策や政治的転覆をはかり、北朝鮮の状況を複雑化させることができる。
●第二次朝鮮戦争の戦後処理と長期政策についてアメリカと中国が同意するなら、両超大国の長いより良い関係を築きうる。したがってこの可能性が高い。
●第二次朝鮮戦争がもしも起こるとすれば、その目的は朝鮮半島の非核化である。
●アメリカは通常兵器を使用し、北の核兵器のありかを発見しそれを破壊するだろう。アメリカは報復のためでも核兵器を使用しないだろう。
●アメリカ軍の侵攻の場合、北朝鮮は核兵器を使う誘惑を受けるだろう。隣国の一つにまず一つ核を使い、より広範囲の核攻撃で脅しながら、停戦という政治的譲歩を引き出そうとするだろう。
●もしもこの脅迫による譲歩があったとすると、弱小国は強大国に対して、核兵器が政治的に利用できると理解し、核兵器はより拡散する危険が増大する。
●北朝鮮の緊張にもかかわらず、中国と日本とともに韓国は経済的に発展してきた。
●朝鮮半島での戦争はこの経済的成功に大きな打撃を与えるだろう。多くの製品とサービスの生産はストップするだろう。空路と海路の交通も停止するかもしれない。朝鮮半島と日本と中国の地域では、保険と移動の費用が高価になる。
●中国がアメリカと軍事的に対立する可能性は低いが、経済的に影響を受ける。投資は減少し、延期され、別の場所に逃避させられるだろう。
●もしも中国が北朝鮮を援助するようなことがあれば、アメリカは北朝鮮への経済制裁を中国にも拡大させるかもしれない。そうなれば中国もアメリカに経済的に報復する（アメリカの国債市場や中国へのアメリカ企業の投資）可能性がある。
●戦争の費用と戦後処理に莫大なコストがかかる。戦後朝鮮半島の統一後、北に多くの投資があるだろう。しかし統一のための費用は韓国が支払うことになるだろう。
III. The Shadow of Escalation
China's Response
CHINA'S REACTION TO a US preventive strike on North Korea is hard to predict. The collapse of one of its few allies followed by the advance of US troops towards its own border would risk humiliating its leadership. Moreover, there are an estimated 1 million Chinese citizens living in South Korea, of whom around 100,000 are reported to live in the Seoul area. All would potentially be at risk from North Korean retaliation and the turmoil that would follow.1
China is also concerned at the prospect of large numbers of refugees fleeing across its border, creating instability in neighbouring areas of its territory.2 There are already indications that China is reinforcing its military presence near its border with North Korea in preparation for a possible war.3 A retired People's Liberation Army general has suggested that China would need to establish refugee camps on its territory in the event of conflict.4
Beyond such defensive measures, some form of Chinese military intervention would be quite likely, both to ensure that US (or allied) forces did not reach its own border and to maximise its leverage in shaping the political order that emerges in the wake of occupation. It might, for example, seek to occupy a buffer zone in adjoining areas of North Korea, including the Yongbyon nuclear complex and the Punggye-ri nuclear test site, both of which are within 100 km of the Chinese border.5 If it were also to use such an intervention to protect the regime, or at least some elements of it, the chances of confrontation with advancing US and South Korean troops would be high.
In order to avoid such an escalation, it would be in the interests of both the US and South Korea to reassure China that they were prepared to take steps to meet its concerns. China might insist on the removal of all US troops from the territory of a newly unified Korea in return for its own cooperation. In the absence of substantial reassurances of this sort, and even if it were not prepared to intervene militarily, China would have many other ways to complicate North
Korean stabilisation, for example through economic pressure and political subversion. On the other hand, if the US and China were to agree a longer-term political settlement for post-war Korea, endorsed by the UN Security Council, it might go a long way towards improving the wider relationship between the two superpowers. The stakes would therefore be very high indeed.
Nuclear Consequences
If a new Korean war were to take place, one of its central purposes would be to ensure the denuclearisation of the Korean Peninsula, and thereby reduce the global total of nuclear-armed states from nine to eight. Its course and outcome would be followed closely by other states that might be considering the acquisition of a nuclear capability.
Trump has reportedly asked for advice on how to certify that Iran is no longer compliant with the nuclear deal enshrined in UN Security Council Resolution 2231.6 If the nuclear deal were to break down as a result, and Iran were to revive its efforts to acquire nuclear weapons, past debates on US and Israeli military options in relation to Iran could soon return to the policy debate. It is hard to imagine that the US would want to be involved in major conflicts against significant state adversaries in two regions at once. But concerns over a possible US attack on Iran could increase if Trump had demonstrated his willingness to take action over North Korea.
The consequences for global nuclear regimes would reach even further if nuclear weapons were actually used. There has been some talk that the US would consider the use of its own nuclear weapons in retaliation for a North Korean nuclear attack.7 However, such a step would be both operationally unnecessary and morally unacceptable. Once their locations are known, the vast majority of militarily relevant targets in North Korea can be destroyed using conventional capabilities. Even where bunkers are located below the depth that conventional munitions can reach, the extent of likely US air superiority is such that alternative conventional means could be deployed to seal such facilities until ground troops can reach them.
Using US nuclear weapons solely as a means of revenge would be even less morally acceptable and would inflict lasting damage on America's international reputation. Inflicting massive suffering on the North Korean people in response to a programme for which they had no responsibility, and without any operational rationale for doing so, would be blatantly contrary to international law on the need for proportionality (in relation to the objectives sought) and discrimination (in relation to non-combatants) in armed conflict. If the president were to order such a step, the defense secretary and all those in the chain of command would be obliged to carry out his order.8 It is hard to imagine, however, that Trump would be prepared to order such a step.
It would be vital to the cause of global nuclear order that the first use of nuclear weapons since 1945 (in this case, by North Korea) was seen to be entirely counterproductive. In the event of an invasion, the North Korean government could be tempted to use a nuclear weapon against one of its neighbours and then demand political concessions, such as a ceasefire, as the price for not repeating the strike on a larger scale. Yet if, as a result, nuclear weapons were seen as having political utility for a weak state confronting a major power, the consequences for wider nuclear proliferation could be very serious.
Economic Uncertainties
Despite continuing tensions, the Korean Peninsula – and indeed northeast Asia as a whole – has been at peace since the 1950s. Partly as a consequence, it has become one of the most economically dynamic regions in the world, with two of the world's three largest economies measured by total GDP (China and Japan). The South Korean economy alone was estimated to be 10% larger than Russia's in 2016.9
A major war on the Korean Peninsula would have profound consequences for this economic success. First, the short- to medium-term effect on South Korea itself would be substantial. If a war involved attacks on Seoul and other urban centres, production of many goods and services would stop. Global companies, including Korea-based Samsung, have come to rely on South Korean suppliers for key, often hi-tech, components, and would have to incur substantial costs in finding alternative sources. Air and maritime traffic would be disrupted, and perhaps halted, with insurance and shipping costs rising sharply for the region.
While the chances of China getting embroiled in a major conflict with the US appear to be quite low, a war could still have a dampening longer-term effect on its economy, with increased political uncertainty in the wake of a major threat to China's interests in its neighbourhood. Investors would become increasingly wary of over-exposure to the region, postponing decisions or moving capital elsewhere. A new Korean war might also deepen wider US–China tensions, thereby increasing the chances of new economic sanctions, for example in relation to trade or investment. If China were to provide support to a North Korean insurgency, some in the US might call for strategic sanctions (of the sort now being applied to Russia) to be extended to China. The Chinese government also has a range of retaliatory measures which it could consider – for example in relation to the US bond market or US corporate investors in China.
Not least, there would be substantial direct costs as a result of the war and its aftermath. Substantial refugee flows would be likely, especially if a conflict were to be protracted. Post-war unification would lead to massive demands for new investment in the North. It would be in the interests of the wider international community – the US, China, Japan, Europe, the UK, brought together by the UN and international financial institutions – to contribute to making this a success. But the largest share of the financial cost of unification, and most of the human energy required, would fall to South Korea, which would also be faced with the costs of repairing the damage to its own territory from the war. There might over time be economic advantages from having access to a large additional workforce, especially given South Korea's rapidly ageing population, but such potential gains, which would in any case be dependent on political stabilisation, would pale compared to the likely costs of reconstruction and investment.
1. Franz-Stefan Gady, ‘Would North Korea Risk the Death of 10,000 Chinese Citizens to Capture Seoul?', The Diplomat, 4 May 2017.
2. Eleanor Albert, ‘The China–North Korea Relationship', Council on Foreign Relations, 5 July 2017.
3. Adam Mount, ‘How China Sees North Korea', The Atlantic, 29 August 2017.
4. James Griffiths and Serenitie Wang, ‘Is China Reinforcing its Border with North Korea?', CNN, updated 26 July 2017.
5. Frank Aum, ‘North Korea and the Need for A US-ROK-PRC Dialogue', US Institute of Peace, August 2017, p. 4.
6. Gardiner Harris and David E Sanger, ‘Trump May Make Congress Decide Future of Iran Nuclear Deal', New York Times, 7 September 2017.
7. Fred Kaplan, ‘Don't Panic about North Korea', Slate, 5 September 2017; Ralph Peters, ‘Here's How to Take out North Korea's Nukes', New York Post, 9 August 2017.
8. For further discussion, see Sarah Grant and Jack Goldsmith, ‘What if President Trump Orders Secretary of Defense Mattis to Do Something Deeply Unwise?', Lawfare, 22 August 2017. The provisions of the 25th Amendment to the US Constitution, which provide for the removal of the president when deemed unfit for office, might be invoked in such circumstances, but would require the agreement of two-thirds of the members of both houses of Congress. See Joel Goldstein, ‘Trump Opponents Have Rediscovered the 25th Amendment. Here is What You Should Know about it', Washington Post, 7 June 2017.
9. International Monetary Fund, ‘World Economic Outlook Database', April 2017.