The mass killings, large-scale gang rape and large-scale expulsion of the Rohingyas from Myanmar constitute one of the most repugnant world events in recent years. This article addresses the question of whether armed humanitarian intervention would have been morally permissible to protect the Rohingyas. It approaches the question from the perspective of the jus ad bellum criteria of just war theory. This approach does not yield a definitive answer because knowing whether certain jus ad bellum conditions might have been satisfied (...) is difficult to judge without detailed knowledge of military intelligence assessments. Nevertheless, I argue that there was just cause for intervention according to both liberal and communitarian perspectives; that legitimate authority in the form of United Nations Security Council authorization would not have been morally necessary; that it is doubtful whether permissible intervention would have required humanitarian intent; that in late August 2017, intervention might well have been a last resort, but that morally relevant facts suggest intervention might have been disproportionate and lacked a reasonable chance of success, such that, all things considered, it would have perhaps been impermissible. -/- (Free access via third external link). (shrink)