Mordechai Kremnitzer emphasizes retribution as a rationale of punishment for international crimes, opposing the claim that it should be dismissed or marginalized. While not rejecting deterrence, he brings forward a number of reasons why the retributivist rationale is important. First, for Kremnitzer only punishment based on retribution is morally justified and, in particular from the offender’s human dignity, legitimate. Second, retribution helps to secure the principle of proportionality in sentencing in international criminal law and in this way counter the dangerous trend of overpunishing the ‘small fish’ – in particular ‘victimizers-victims’, i.e., ‘Kapos’ or child soldiers – while underpunishing the big ones. In this regard, Kremnitzer develops the ‘theoretical move’ that retributive justice should be implemented by the ‘principle of conservation of criminal energy’: the ‘small fish’s’ reduced guilt serves as aggravating circumstance to the deeds of the ‘big fish’. As a result, the ‘big fish’ should be in the focus of any prosecutorial strategy of international criminal tribunals, and the problem of (vertical) selectivity due to limited state cooperation should be overcome by (fair) trials in absentia.