Why the UK Needs to be Thinking Now about a Possible Korean War

Trump’s military advisers are warning him that, the more progress North Korea is able to make, the greater the damage its missiles would be able to inflict on America’s major cities in a retaliatory strike. Even as such a prospect becomes ever closer, however, the heads of the CIA and the US military have made clear that a North Korean ICBM capability is ‘unacceptable’ and ‘unimaginable’.

Yet, even if war were to start in the next few months – before North Korea has the capability to threaten the lower states of the US – its consequences for the region would be more devastating than any conflict that America has faced since 1953. Within the first few weeks, there could be hundreds of thousands of casualties in both North and South Korea, including the deaths of thousands of US military personnel and civilians. If China also gets involved militarily, or if nuclear weapons are used, it could be a lot worse. International trade and investment would suffer as economic activity slumped in one of the globe’s most productive regions.

Given these catastrophic consequences, it is still hard to imagine that the US will be willing to start a war. Yet, if diplomacy and sanctions fail to work, as now seems possible, Washington will have to move to a policy of containment and deterrence, hoping that credible US threats of retaliation will limit the danger that Pyongyang’s nuclear arsenal could soon pose. Any other recent president would probably have adopted such an approach, calculating that the ‘unacceptable’ consequences of living with an ICBM-capable North Korea were still less onerous than the bleak certainties of catastrophe which starting a war would leash.

Judging by his recent threat to ‘unleash fire and fury like the world has never seen’, Trump could well be different. We simply do not know. But the time pressures now being created by North Korean technical advances, together with Trump’s volatile and impulsive personality, is a dangerous mix.

What we do know is that, if war did begin, the president would be on the phone to 10 Downing Street within an hour asking for support. Russia and China would demand an immediate UN Security Council meeting. The world’s media would be dominated by round-the-clock coverage of the evolving crisis. The British prime minister would then have only a few hours, at most, to make clear how she stood on what would be one of the most momentous strategic shocks of the post-Cold War era.

Her decision would have as profound an impact on the UK’s international standing, and on its domestic politics, as the fateful decision to stand shoulder-to-shoulder with the US in the run-up to the 2003 invasion of Iraq. However, there would be little time for multiple consultations and deliberations before positions had to be taken. The die would be cast on Day One. Whitehall needs to be preparing now for a range of possible scenarios that could unfold in the coming months.

Much would depend on how the war starts. North Korea, for example, might retaliate if the US shoots down a test missile being fired into the waters around Guam. Or it could interpret a massing of US forces on its border as the precursor for invasion. If it was clear that North Korea was responsible for initiating a conflict, it would be difficult for the UK not to provide strong political support for its closest ally.

Both Japan and South Korea, despite their current opposition to US preventive strikes, would also have no alternative but to provide military and logistical support to their ally once a war had begun and the lives of their citizens were being lost. They would look to the UK, Australia and other Western countries to do the same. And the US would remind its NATO allies that the roots of the crisis lie in North Korea’s increasingly successful efforts to acquire a nuclear capability that is on course to threaten much of Europe, as well as the lower states of the US. London and Paris are around the same distance from North Korea as Los Angeles, as an ICBM flies.

The UK government might be able to draw some relief from the fact that it had received no notice of the US strikes, and could not therefore be expected to provide a military contribution of its own. However, it would have to decide quickly how it might view such requests if they were to be made, most likely for RAF and special forces capabilities.

If the conflict were seen as having been initiated by Trump, it would be difficult for the government to secure a parliamentary majority to send UK military assets to Korea. Perhaps the most important UK contribution, if war does break out, might therefore have to be diplomatic. The wider international community (led by the UN and international financial institutions, with European support) could play an important role in brokering negotiations between the key parties directly involved, designed to prevent escalation to a US–China conflict and bring the war to a rapid end.

A central guiding principle should be that the eventual settlement be designed to ensure that neither the US nor China feels that the other has made substantial strategic gains. If US military strikes do take place, and an invasion follows in order to finish the job, China would have understandable concerns if the forces of the US and its allies were subsequently to be advanced right up to its own 880-mile border with Korea. If the stability and peace of Northeast Asia is to be restored after a conflict, therefore, it will have to be underpinned by recognition of the need for geopolitical balance. Otherwise, as in Europe’s ‘reunification’ after 1990, the unification of Korea could lead to a new Asian Cold War from which no one would gain.

Whatever stance it takes, it will be difficult for the government to sustain, given the far-reaching global consequences of a new Korean War and the febrile nature of UK domestic politics. That is all the more reason for Whitehall to be doing preparatory work now for what is no longer an unthinkable scenario, and for the government to align itself with those who are now urging the US to reject calls for preventive strikes. As the Report of the Iraq Inquiry (Chilcot Report) concluded:

The UK’s relationship with the US has proved strong enough over time to bear the weight of honest disagreement. It does not require unconditional support where our interests or judgements differ ... [T]he lesson is that all aspects of any intervention need to be calculated, debated and challenged with the utmost rigour.

Malcolm Chalmers
Deputy Director-General, RUSI

The views expressed in this article are those of the author, and do not reflect those of RUSI or any other institution.