It is a fundamental tenet of the laws of war that they apply equally to all parties to a conflict. For this reason, a party such as Russia — that illegally launches a war — benefits from all the same rights as a party such as Ukraine — that is forced to defend against the illegal aggression. Countless philosophers have shown that this so-called equal application doctrine is morally indefensible because defenders should have more rights and fewer responsibilities than aggressors. Legal scholars continue to support the equal application doctrine, however, because they reasonably fear that applying different rules to different warring parties will dramatically undermine compliance with the international humanitarian law system as a whole. In previous work I have sought to bridge this divide by shifting the focus from the application of international humanitarian law rules to their enforcement. Specifically, I have advocated retaining the equal application doctrine but reducing its inherent unfairness by disproportionately prosecuting aggressors. To that end, I developed a doctrine that I call “the unequal enforcement doctrine.” This Article advances the doctrine in several key ways, but it makes two particularly significant contributions. First, the Article answers a series of core questions regarding the implementation of the unequal enforcement doctrine. Second, the Article applies the unequal enforcement doctrine retrospectively to prosecutorial decisions made in all of the International Criminal Court (“ICC”) situations that have progressed as far as trial. Doing so reveals that, although the ICC did not expressly consider the aggressor status of parties to the conflict when selecting cases, that status has likely been influencing prosecutorial decisions all along, sub silentio. Indeed, this Article’s analysis provides powerful support for my claim that “who started it” matters intuitively and profoundly and that the answer to that question has significantly impacted international criminal prosecutions.