The collapse of the Yugoslav Federation and the series of wars that subsequently engulfed the region in the 1990s will be remembered for brutalities and war crimes (including genocide) not seen in Europe since the end of the Second World War. As a result of the war crimes in progress—especially those taking place in Bosnia—in 1993, the United Nations’ Security Council established the International Criminal Tribunal for the Former Yugoslavia (ICTY, also known as The Hague Tribunal) to scrutinize and prosecute violations of international humanitarian law and crimes of genocide in the former Yugoslavia. Subsequently, between 1993 and 2017, the ICTY charged more than 160 persons, including heads of state, prime ministers, army chiefs-of-staff, interior ministers and many other high- and mid-level political, military, and police leaders from various parties to the Yugoslav wars. The charges and convictions included the gravest international crimes: genocide, crimes against humanity, violations of the laws or customs of war, and grave breaches of the Geneva conventions. By placing some of the most senior and notorious criminals on trial and holding them accountable, the Tribunal’s ultimate aim was to pave the way for inter-ethnic reconciliation in the former Yugoslavia. There was also an expectation that the transparent judicial process and subsequent prison sentences handed down to a number of war criminals would lead to their own and their followers’ ideological catharsis and ethnocentric deradicalization. However, upon release, many of the sentenced war criminals have been welcomed as heroes by their ethnic communities and political elites, with the crimes they were sentenced for becoming their political capital rather than causing them to be shunned. Hence, instead of paving the path for reconciliation, the ‘old’ war criminals have become a source of inspiration to a new generation of radical nationalists in the region and beyond. By focusing on several prominent war criminals who have completed their prison sentences—including Biljana Plavšić, Momčilo Krajišnik, and Vojislav Šešelj—this chapter discusses the failure of the ICTY and the wider international justice system to deradicalize individual criminals and discredit their war-time legacies in the former Yugoslavia. In particular, we analyse how political elites and local communities in the region have responded to the return of the sentenced war criminals to their home regions, and how war crimes in the former Yugoslavia have fueled extremism and a new wave of white supremacist terrorism internationally.