One hundred and forty years ago, the British statesman Sir William V. Harcourt, writing under the pen name Historicus, defined intervention as “a high and summary procedure that can sometimes snatch a remedy beyond the reach of law. As in the case of revolution, its essence is its illegality and its justification is its success.” This definition has not been improved upon since Harcourt’s time. He points to the illegality of intervention, well aware that to codify the practice would be to legislate for imperial adventures. But he nonetheless allows for exceptions, instances when the rule can be broken in pursuit of a higher good. And he identifies the criterion in such instances: success. Intervention is a matter of policy rather than law. As well as considering intervention alongside revolution, he might also have made the comparison with invasion; intervention is an act of war, and as such is politics conducted by other means.

Intervention, Not War?

Most contemporary debates treat military humanitarian intervention and its younger sibling, the responsibility to protect (R2P), as matters of law. But perhaps because of the implication that “humanitarian” actions are above criticism, and because the reality of war is clouded by the euphemism “intervention,” there has been too little comparative and historical analysis of the topic. Still less have recent humanitarian interventions been studied as instances of aggressive war – albeit arguably “just war.” This essay explores the contemporary history of humanitarian intervention, arguing that Harcourt’s skepticism is as warranted today as it was when he discouraged the British Parliament from voting to intervene in the American Civil War.

Subjecting war to regulation is both necessary and hazardous. Most ethical traditions contain a concept of just war, and the concepts of restraining excessive violence and respecting at least minimum standards of humanity in wartime are as old as the practice of war itself. There are rich traditions of scholarship on these issues, the best ones informed by a somber appraisal of the inevitable shortcomings of trying to restrain war in any way. Carl von Clausewitz’s maxims and observations remain true: he noted that war tends toward the absolute in a ratchet of escalation; decisions are clouded by the “fog of war” and their implementation is impeded by “friction” that makes the simplest actions extraordinarily difficult to carry out. The label of “humanitarian” does not make military action any easier.

In the era of Harcourt and Clausewitz, the European imperial powers’ technical superiority on the battlefields of Africa and Asia was matched by their own moral hubris. The Gatling gun was seen as the agent of philanthropic imperialism, bringing civilization to the benighted natives (at least those who survived the first encounter). As the Ottoman Empire decayed, intervention to save threatened Christian minorities in Muslim lands was rarely questioned, save on the grounds of expense and prudence. Britain’s right, indeed duty, to intervene in Sudan – first to suppress the slave trade and later to avenge the death of General Charles Gordon – was conditional only on the right conjunction of circumstances arising. Only in the 1920s and 1930s, when the right of intervention was applied within Europe and especially when it was cited by Adolf Hitler to justify the annexation of the Sudetenland, was the doctrine discredited. Chapter VII of the UN Charter makes no provision for humanitarian intervention, only for war conducted against an aggressor at the behest of the world community, as in Korea and Kuwait. The 1948 Genocide Convention is silent about the means required to “prevent and punish” the crime of genocide, and it would have been an anomalous anachronism for the member states of the UN to have made an exception to its rule of outlawing aggressive war by specifying that genocide created a duty of intervention.

The UN Charter also makes no mention of peacekeeping. That was an inspired ad hoc innovation dreamed up by Lester Pearson, Canadian Secretary of State for External Affairs, during the Suez crisis in November 1956. The idea that a neutral armed force can be invited by two belligerents to supervise their truce is a remarkable one. Under strictly-circumscribed conditions, it can work. Fifty years of UN peacekeeping operations confirms the basic requirement: there must be a peace to keep. Sending “peacekeepers” into the middle of active hostilities is a recipe for failure, every time. Nonetheless, the idea of dispatching troops that could actually enforce peace or provide physical security to threatened populations has crept into popular debate as an extension of peacekeeping rather than as a variant of the just war.