Sloane on Jus ad bellum and in bello

Following discussions in relation to the legality of the armed conflict in Gaza and the alleged violations of international law by the two belligerents (see here, here and here), some of you might find Professor Sloane’s recent paper, titled “The Cost of Conflation: Preserving the Dualism of Jus ad Bellum and Jus in Bello in the Contemporary Law of War”,  just published in Yale Journal of International Law, interesting.  In it, Professor Sloane deals with the influence that the legality of a jus ad bellum decision has on the judgement of the legality of jus in bello actions.  For instance, while defending the dualist axiom, i.e. the notion that one is not necessarily contingent on the other (e.g. an unjust war can be fought justly and a just war can be fought unjustly), noting that the axiom is indispensable to the law of war, he argues that international law

must recognize that, descriptively, discretionary in bello judgments—in particular, about in bello proportionality—at times vary depending on oft-politicized characterizations of the perceived justice or legality of conflicts. That is, they vary, contrary to the dualistic axiom, based on ad bellum judgments. That does not mean that they should. But they do. Despite nominal consensus on the dualistic axiom, international law tends to tolerate more incidental civilian harm (“collateral damage”) if the alleged casus belli is either (1) widely perceived as legal (for example, a clear and unassailable case of self-defense) or (2) formally illegal but still perceived as legitimate, meaning that it furthers broadly shared international values: preserving minimum order, halting human rights atrocities, and so forth

while noting that the goals of international humanitarian law

cannot be reduced to a simple formula or justified by a single moral theory; rather, they instantiate a complex blend of deontology, teleology, and virtue ethics.

Sloane concludes, while criticising the ICJ’s jurisprudence on the issue, with a strong defence for the war of law to attempt to preserve the dualist axiom.

The paper is very timely, well-worth reading and highly recommendable and Sloane deserves credit for addressing this very important issue.