Historically, what we today call international criminal law was primarily adjudicated before domestic courts. This chapter discusses the jurisdictional bases for prosecuting international crimes with reference to a survey of cases proceeding in foreign courts and involving events in Syria. When it comes to crimes committed during the Syrian conflict, domestic courts have emerged as fertile grounds for justice given the failure of the International Criminal Court referral effort, the lack of multilateral support for a hybrid or ad hoc tribunal devoted to Syria, and the perceived legal impediments to building international justice institutions outside the Security Council. A number of domestic trials involving events and actors in Syria are underway on the basis of diverse principles of jurisdiction and featuring a range of criminal charges and fact patterns. These cases fall into two general buckets. One set of cases involves foreign fighters who have returned home to face charges under anti-terrorism legislation or laws criminalizing their participation in foreign wars. A second subset of cases involves individuals who stand accused of committing international crimes stricto sensu. These latter cases are enabled by the incorporation of international criminal law into domestic penal codes, a global legislative trend occasioned in part by the ratification of the Rome Statute (even though that treaty technically does not require domestic incorporation of ICC crimes). Facilitating these cases is the proliferation of special prosecutorial units dedicated to investigating international crimes; global mutual legal assistance arrangements; the formation of joint investigative teams focused on the prosecution of transnational crimes; training programs dedicated to investigating international crimes; and Europe-wide institutions such as EUROPOL, the European Arrest Warrant (EAW), and the Eurojust Genocide Network. This jurisprudential survey yields a number of interesting observations. First, the cases skew towards terrorism, as opposed to atrocity, charges. Given the broad reach of material support for terrorism statutes, these crimes are easier to prove with available evidence and also respond to sovereign national security priorities. Second, most of the existing indictments involve single incidents (rather than large operations or systemic abuses). To the extent that war crimes charges are forthcoming, they tend to involve relatively minor charges, often for lack of evidence of more serious crimes that are implied by the proof at hand. Third, from the perspective of trends in the defendants involved, most indictments tend to focus on low-level perpetrators, rather than the architects of violence or those most responsible. Fourth, and also troubling, is that the vast majority of cases that have moved forward have targeted members of opposition groups — including ISIL members — rather than Syrian government personnel. Senior figures, and regime actors, have simply not traveled to Europe or elsewhere that these cases are being pursued. As a result, investigations against Syrian government perpetrators have remained aspirational works in progress. That said, national authorities are increasingly organizing structural investigations on the conflict and its various armed groups, which allow them to move quickly against particular individuals as soon as they are within reach. Fifth, as is apparent from the available evidentiary records, many of these cases are benefiting from the sophisticated documentation work of non-governmental organizations that are sharing their holdings with national authorities. Sixth, and finally, the testimony of asylum-seekers and others who have sought refuge in the prosecuting state has proven crucial, attesting to the importance of prosecutorial authorities building trust and genuine connections with Syrian diaspora communities. All told, while important, these domestic proceedings remain episodic and opportunistic. Given the investigatory and prosecutorial realities, the cases in the aggregate are not representative of the full scope of the international crimes being committed in Syria. Although these results are disappointing if the goal is comprehensive accountability, these cases are establishing important legal precedents, providing domestic authorities with valuable experience prosecuting international crimes, offering a measure of justice to victims, and punishing individuals accused of horrific acts. In addition to putting a dent in impunity and denying safe haven to perpetrators, cases in foreign courts promote stability by preventing victims and victim groups from taking justice into their own hands in their places of refuge. Even singular cases can be highly salient and can exert a multiplier effect, signaling that justice is possible and helping advocates overcome political resistance elsewhere. When situated against the obstacles to exercising international jurisdiction, these results should be celebrated, since domestic courts have emerged as the only potential forum to administer justice for Syria to date.