The Right of Conquest: Ukraine, Gaza, and the Prize of Victory

The right of conquest is presumably not a topic anyone expected to be in the news in 2025. Yet, regrettably, lamentably, here we are. President Vladimir Putin has proclaimed Russian sovereignty over territories acquired by forceful means from Ukraine.[i] Similarly, members of the Israeli government have announced their intention to retain an IDF presence in Gaza indefinitely, and even to establish Israeli sovereignty—by force—over the West Bank.[ii] 

While the horrors that are unfolding daily in Ukraine and Gaza must remain to the fore of our minds, I want to devote this short essay to reflecting on the issues raised by the Russian and Israeli governments’ incipient claims to legal title over these disputed territories. These claims, I will argue, raise a series of uncomfortable but profoundly important questions for scholars interested in the ethics of war.

Winner Takes it All?

Our focus is the political claims to govern or annex a particular territory that arise from victory in war. Claims of this sort have historically been asserted as ‘the right of conquest.’[iii] To the victor, it was assumed, went the spoils of war. It was, for example, on the basis of its military victory in the Franco-Prussian War of 1870-1 that the German Empire claimed title over the disputed region of Alsace-Lorraine. This was consistent with the legal practice of the time.

As Sharon Korman explains, ‘the proposition that a state that emerges victorious in war is entitled to claim ownership or jurisdiction of territory of which it has taken possession during a war was (until relatively recently) a recognized principle of international law.’[iv] This was a feature, not a bug, of the system. If war was to function as an instrument of decision, it was essential that states accepted the verdict of battle as final and determinative.[v] 

War thus functioned almost like an ordeal, wherein states proved their right to certain territories by winning military victories over rival claimants. This norm has, of course, since lapsed. It was repudiated by states in the aftermath of the First World War, and its proscription was formally codified in the Covenant of the League of Nations and the United Nations Charter. Few states or legal scholars today recognise the right of conquest.

Urgent Questions

The legal situation in respect of the right of conquest is not in question. Where once it was supported by international law, it is now strictly ruled out. But this leaves several important questions still unasked, let alone answered.

The first set of questions pertain to cases when the side fighting for a just cause prevails in battle. What entitlements or rights, if any, follow to the just victor on account of its success in battle? And on what grounds do these entitlements rest? Were they, for instance, generated by the ‘raw fact of victory’ itself, by the underlying justness of the cause, or by some combination of the two?[vi] 

The second set of questions bear on cases where the side fighting an unjust war emerges from combat as the winner. What, if any, rights or entitlements should this unjust victor be permitted to claim? These questions are not just of academic interest. They have clear purchase when it comes to the situation we are currently confronting in both Ukraine and Gaza. As such, they require urgent attention.   

Old Answers

One might expect the literature on jus post bellum to furnish some answers to, or at least give us some grip on, these questions. That is not the case. While jus post bellum scholarship has a lot to say about the responsibilities of victors in the aftermath of a just war, it says next to nothing about the rights of victors.

For a meaningful treatment of these questions, one has to go all the way back to the early modern legal theorists, Alberico Gentili and Hugo Grotius. I do not intend to delve into their writings here—readers are welcome to do that for themselves.[vii] What I will do, however, is gloss the general concerns that they raise.

On the one hand, they express reservations about the view that the simple fact of victory itself, regardless of the justness of the cause for which it was won, can be generative of rights to territory. Their worry is that this way of proceeding veers dangerously close to the doctrine of might is right. Further, it contravenes one of the central tenets upon which the idea of law rests, namely, that legal rights should never follow from illegal acts.[viii] Or, as it is rendered in Latin, ex injuria jus non oritur.

On the other hand, they also warned that it is imprudent to refuse to recognise any post-war settlement that granted legal rights or entitlements to unjust victors. The reasons for this are obvious. First, it assumes that it is possible to distinguish, so to speak, the good guys from the bad guys; this is rarely the case. Second, it undercuts the capacity of war to function as an instrument of decision. Indeed, it would both confer license upon the vanquished party to recommence hostilities at any time to right the wrong that has been done to them, while incentivizing the unjust victor to prevent this from happening by not just defeating its enemies in the first instance, but by thoroughly routing them.

Ultimately, Gentili and Grotius concluded that victory in war could be generative of rights, including in some cases the right of conquest. And they accepted (albeit in a heavily qualified manner) that this principle could be applied to victories that were won in both just and unjust wars. Their reason for plumping down on this side of the issue was their determination to maintain war’s utility as an instrument of decision. If the outcome of a war was not by itself sufficient, but instead had to be in alignment with justice, to conclusively resolve and indeed terminate a conflict, this would be a recipe for never-ending hostilities. Better to avoid this, Gentili and Grotius believed, and so they opted for this pragmatic but problematic way of thinking about how wars should be ended.  

Endgame

Grotius and Gentili alert us to the need to think more carefully and deeply than we have hitherto done about how we understand the endgame phase of modern armed conflict, and how we ethically evaluate it. The questions that the Russian and Israeli governments are obliging us to confront are both painful and perplexing. They tempt the international community to acquiesce to a rotten deal: an end to fighting in exchange for accepting Russian and Israeli claims to sovereignty over conquered land.

While Gentili and Grotius furnish us with a conceptual vocabulary for evaluating situations such as this, I have trouble accepting that the answers they arrive at are right for us today. We have witnessed too much horror in both Ukraine and Gaza to entertain the idea that Russia and Israel should benefit from their criminal actions. With so many other rights currently being trampled on, why would we choose this moment to revive the right of conquest? It simply cannot be right. Besides, the idea that war can still serve as an instrument of decision appears not just dated but deeply anachronistic.[ix]

The challenge confronting us, then, is not just to engage with the claims put forward by the Russian and Israeli governments, but to surface the deeper lying beliefs that they rest upon. This will require scholars interested in the ethics of war to think again, not just about the responsibilities of victors, but the rights and legal entitlements that winning a war generates for them. By grasping this nettle, we can equip ourselves to more adequately respond to—and indeed contest—the claims currently being advanced by the Russian and Israeli governments.  

Cian O’Driscoll is a Professor of International Relations at the Coral Bell School of Asia Pacific Affairs, ANU. He has written extensively about the ethics of war. His most recent monograph is Victory: The Triumph and Tragedy of Just War (Oxford University Press).

[i] Kateryna Denisova, ‘Ukraine Won’t Recognise Occupied Territories as Russian as Part of any Peace Deal, Zelensky says’, Kyiv Independent, 9 March 2025. Available at: https://kyivindependent.com/ukraine-wont-recognize/. Accessed: 1 June 2025.

[ii] Leonie Fleischmann, ‘Israeli Plan to Occupy all of Gaza could Open the Door for Annexation of the West Bank’, The Conversation, 9 May 2025. Available at: https://theconversation.com/israeli-plan-to-occupy-all-of-gaza-could-open-the-door-for-annexation-of-the-west-bank-256029. Accessed: 1 June 2025.  

[iii] Jospeh O’Mahoney, Denying the Spoils of War: The Politics of Invasion and Non-recognition (Edinburgh: Edinburgh University Press, 2018), p. 3.

[iv] Sharon Korman, The Right of Conquest: The Acquisition of Territory by Force in International Law (Oxford: Clarendon Press, 1996), p. 1.

[v] James Q. Whitman, The Verdict of Battle: The Law of Victory and the Making of Modern War (Cambridge, MA: Harvard University Press, 2012).

[vi] Brian Orend, ‘Jus Post Bellum’, Journal of Social Philosophy 31:1 (2000), p. 122.

[vii] I explore their views on this matter at length elsewhere: Cian O’Driscoll, Victory: The Triumph and Tragedy of Just War (Oxford: Oxford University Press, 2019), pp. 95-106.

[viii] Korman, The Right of Conquest, p. 94.

[ix] See: Russell Weigley, The Age of Battle (Indiana University Press, 2004).

Disclaimer: Any views or opinions expressed on The Public Ethics Blog are solely those of the post author(s) and not The Stockholm Centre for the Ethics of War and Peace, Stockholm University, the Wallenberg Foundation, or the staff of those organisations.