Are humanitarian interventions obsolete? Or does historical experience teach us that the willingness of the international community to intervene within other states for humanitarian motives will ebb and flow with time? The catastrophic effects of nato’s intervention into Libya, and the damaging experiences of state-building in Afghanistan and Iraq appear to have put an end to two decades of liberal interventionism,¹ at least for the foreseeable future. These experiences have prompted a turn in political and academic discourse away from intervention and state-building towards atrocity prevention and non-forceful alternatives to crisis management. Members of the international community have instead opted for other coercive – but non-forceful – measures such as economic sanctions, tighter embargoes, and international prosecutions to vilify perpetrators and pursue protection outcomes for targeted populations without resorting to full-scale military intervention. As the shape of world order continues to evolve, and the rise of new powers leads to renewed debate over whether our existing international institutions can ensure the protection of fundamental human rights, scholars and policymakers would benefit from reviewing the history of past humanitarian interventions and assessing the extent to which they advanced global stability and justice.

This special issue is the product of a two-day symposium held in September 2021, co-sponsored by the Centre for Geopolitics at the University of Cambridge, the Centre for Grand Strategy at King’s College London, and the journal Global Responsibility to Protect. The symposium took place in the wake of a disastrous withdrawal of US forces in Afghanistan, followed by a rapid takeover by the Taliban. These events exposed the extent of failure of liberal interventionism in Afghanistan. Meanwhile, mass atrocities have continued to be committed in conflicts such as Syria, Yemen, and Myanmar with no prospect of humanitarian intervention in sight. And, as this article went to press, further documentary evidence emerged of potential crimes against humanity perpetrated by China – a permanent member of the United Nations Security Council – in its brutal mass internment of its Uighur population in Xinjiang.² The Symposium sought to make sense of the current landscape of humanitarian catastrophe and international responses to them, in light of long-term historical experiences, and with reference to potential futures for humanitarian protection.

Since the symposium, the international condition has deteriorated significantly; the Russian invasion of Ukraine in February 2022 is a reminder that military intervention is likely to remain a fundamental practice in international relations for the near future. However, to what extent does humanitarian intervention remain a viable option to the international community for responding to mass atrocities and humanitarian crises in the context of war and major instability? The experiences of Ukraine have drawn attention to the effectiveness of regional humanitarian options such as opening borders to millions of refugees and negotiating humanitarian corridors to access besieged populations. Indeed, coercive measures such as economic sanctions – including commitments to reduce European reliance on Russian oil, asset freezes, travel bans, and arms embargoes – have imposed serious economic and political costs on Russia. Western governments have funnelled enormous military support through weapons, funding, and intelligence.

The situation in Ukraine is exceptional – a clear case of an illegal war of aggression against a legitimately elected government, with direct proximity and geopolitical significance to European states. Still, there are no prospects of intervention or even limited military force such as through the imposition of a no-fly zone or drone strikes. The stakes of external military intervention are particularly high in this instance, given the nuclear capabilities on both sides and the likelihood of rapid escalation. Yet this case provides a unique window on the transformed international security environment and the preference of major powers to develop alternative measures to punish and constrain perpetrators, short of the use of force.

The experiences in Ukraine are too recent to be included in this special issue. However, it touches on a range of issues at stake when considering the past, present, and futures of humanitarian intervention. Both the collapse of Western-led liberal interventionism in Afghanistan and the war in Ukraine are (arguably) symptomatic of a rapidly evolving international order. Given the reliance of R2P’s most intrusive tools on the Security Council, Pillar Three intervention specifically, and the appalling spectacle of a P5 member shelling civilians within two miles of the Secretary-General,³ coupled with a broader challenge to the global human rights agenda,⁴ many wonder if R2P has anything left to offer. Have we come full circle and arrived back at a point where R2P no longer offers an effective solution to the problem of mass atrocities in those ‘last resort’ circumstances whereby extraordinary measures are urgently required?

In a world without ‘liberal hegemony’, how will states respond when the perceived moral(/political) imperative to intervene arises? Much will depend upon the degree to which liberal order is rolled back from its global aspirations. Yet, whether a competitive bounded-order emerges to rival the liberal international order in a ‘bi-polar-like’ fashion,⁵ or if global pluralism opens up into a disaggregated ‘multiplex’ plethora of overlapping orders,⁶ the promising illusion of ever-expanding norms of behaviour characterised by political liberalism has faded.⁷ History is no perfect guide to the future – it provides no consistently ideal models of humanitarian interventionism, despite periodic and infrequently successful endeavours.⁸ Still, we can see in history how intervention has operated within geopolitical contexts radically different to the presumption of unipolarity which conditioned the debates of the 1990s and beyond.

It is important to remember that, throughout history, humanitarian interventions have been largely regarded as a breach of the ‘conventional pattern of international order’.⁹ Even during periods where interventions occurred periodically, the practice of non-intervention in the domestic politics of another sovereign state has remained a paramount principle in international diplomacy.

It was during the early-mid nineteenth century that the term ‘humanitarian intervention’ entered the diplomatic vernacular. Until the 1990s, this period witnessed the most frequent incursions that were justified on ethical grounds. Unlike the 1990s, this was not an era of unipolarity but one in which there were multiple great powers, with the British Empire as primus inter pares. The main factor that enabled these interventions was agreement among those powers that any intervention would enhance European stability. As a result, almost all these interventions occurred in the Ottoman Empire, the veritable ‘sick man of Europe’ and the most persistent source of instability within the continental system. The intervening states needed to convince their counterparts that any intervention was not primarily intended to advance their own narrow interests but those of the system more broadly.

Today it is difficult to think of a comparable case that would unite all the Security Council permanent members. The last military intervention to receive any sort of Council backing was Libya in 2011 and it hardly offers a happy precedent, given the subsequent fallout between the major powers over whether the mandate was stretched beyond what was initially agreed in order to justify regime change in Tripoli. In the third decade of the twenty-first century, the Council remains impotent to fulfil the function of preventing the most egregious humanitarian abuses. Consequently, any multilateral basis for atrocity prevention will continue to be the remit of regional organisations, just as nato played the pre-eminent role in the Libyan intervention, and the legality of such interventions will, as a result, remain controversial. In that regard, little has changed since the nineteenth century. Contemporary coercive humanitarian interventions continue to fit the description that the legal theorist, W. V. Harcourt, applied to them in 1863: ‘A high and summary procedure which may sometimes snatch a remedy beyond the reach of law … In the case of intervention as that of revolution, its essence is illegality, and its justification is its success’.¹⁰

The spark for an intervention in the nineteenth century was often pressure from an aggrieved public, particularly in powers with more representative forms of government. Atrocities were communicated back to publics with greater immediacy than ever before by foreign correspondents and missionaries via telegraphic cables. Today, social media and camera phones have quickened the pace at which crimes are beamed around the world but in many ways our contemporary reaction is not altogether different from that of our ancestors. Just as then, particular victims attract greater attention and sympathy, particularly when the nations are closer at hand and their societies more like ours.

A final, historic trend that is evident is the way in which eras of intervention and non-intervention tend to be cyclical. A period of frequent intervention in the early-mid nineteenth century was followed by an era of comparative non-intervention in the late nineteenth century when, as the international environment became more competitive and relations among the great powers became more fraught, humanitarian interventions were increasingly regarded as luxuries that could no longer be afforded. Similarly, after the First World War, disillusionment reigned about the power of arms to serve noble ideals and humanitarian interventions were widely regarded as quixotic adventures that belonged to a bygone era.

Yet, at the same time, these periods of non-intervention are liable to lead to periods of greater intervention if great crimes are allowed to occur with impunity. The British political theorist Alfred Zimmer noted that the ‘decline of international morality’ in the late 1930s stemmed from the failure of the great powers to do anything about previous atrocities, such as the annihilation of the Ottoman Armenians during and after the First World War.¹¹ Since the Second World War, moral disgust at how appeasement emboldened and enabled Hitler and the Axis power has led to the analogy of Munich being frequently employed to justify standing up to dictators. Similarly, the rhetoric of ‘Never Again’ has served as a constant historically informed warning of where unchecked aggression and acts of genocide can lead. After a period where non-intervention has been in the ascendancy, the frequency with which the Munich analogy has been referenced in the current Ukraine crisis might suggest that an era of renewed interventionist fervour might again be upon us.

As briefly introduced below, the opening forum to this issue provides a re-reading of historical legacies and current trends in the practice of humanitarian intervention and their implications for R2P. The articles that follow illustrate the breadth of debate that has emerged during a more recent period of aversion to military intervention, and the pursuit of R2P-outcomes through non-forceful measures.