Notions of 'sovereignty as responsibility' and 'the responsibility to protect' are often framed as radical departures from the 'traditional' conception of sovereignty. Many assume that sovereignty has, until recently, entailed only rights and not responsibilities. In contrast, this article argues that sovereign authority has been understood to involve varied and evolving responsibilities since it was first articulated in the 16th and 17th centuries. It then traces the historical emergence of the tension between the right of sovereign states to be self-governing and free from outside interference and their responsibility to secure the safety of their populations. It cautions against a simplified story of 'traditional' sovereignty which reifies supposedly concrete and ahistorical rights of sovereigns while casting sovereign responsibilities as a morally abstract and late-arriving challenge.

This article seeks to clarify the current legal status of a particular aspect of the 'responsibility to protect' principleçthe idea that bystander states have a collective responsibility to protect populations beyond borders from mass atrocities when host states fail to do so. It outlines the development of this idea and argues that, while the legal force of key international statements on the 'responsibility to protect' principle may be weak at best, the International Court of Justice and the International Law Commission have offered bold declarations in recent years which do point towards the gradual development of legal duties for the extraterritorial protection of populations.

There is a curious tendency among some scholars and commentators to denigrate the impact of the Responsibility to Protect (R2P). Drawing on constructivist scholarship that illuminates both the regulative and constitutive ways that norms matter and that explains how the effects of norms can be interpreted, I argue that the R2P norm has a real and observable impact on the behaviour of states. I demonstrate that this impact can be detected not only in instances of compliance, such as in Libya, but perhaps even more clearly in examples of violation, such as in Syria.

The conventional story of sovereignty told in the discipline of International Relations (IR) tells us that there is a “traditional” or “Westphalian” meaning of sovereignty that has prevailed since the seventeenth century and that accords states the right to govern themselves free from outside interference. In recent years, the tale goes, this meaning has been challenged for the first time by notions of conditional and responsible sovereignty. This article argues that the supposed “traditional” meaning of sovereignty is not as foundational and timeless as is often assumed. Rather than a right of non‐intervention, it was the right to wage (just) war that was first conceived by political theorists to be the external corollary of the internal supremacy of the sovereign. This included the right of war to punish tyranny and rescue the oppressed. This article examines the initial absence and then the gradual emergence of the “traditional” meaning of sovereignty, arguing that it was only firmly established by international society for the first time in the twentieth century. It concludes by considering some of the implications of this revised story of sovereignty for the study of IR.

It is increasingly well understood that concepts of ‘humanitarian intervention’ and the ‘responsibility to protect’ enjoy a long and rich history. Nevertheless, it is surprising how plainly the arguments offered by states seeking to justify intervention in Libya in 2011 echo those used by theologians, jurists, and philosophers to justify intervention in the sixteenth, seventeenth, and eighteenth centuries. Those advocating intervention in Libya drew not just on the language of ‘human rights,’ that emerged relatively recently, but on a wider and much older range of idioms and ideas to make their case. In this article, I identify three key arguments that were employed by states in support of the intervention and I demonstrate their parallels with three principal arguments that have been advanced to justify intervention in response to tyranny since the sixteenth century. The three arguments are: the need to protect ‘innocents’; the need to hold ‘tyrants’ to account; and the need to defend the will of a sovereign people. After exploring each argument, I conclude by noting that the claim often heard today, that intervention is under certain circumstances a responsibility rather than merely a right, also has deep roots in early modern thought.