Whilst recognizing important distinctions between different types of intelligence agency, and a range of possible contradictions between the imperatives governing the two types of agency, it is necessary to overcome the one-side quality of much existing literature, whose critique of the subversion of the rule of law by intelligence agencies tends to preclude any appreciation that such agencies can play a supportive role for war crimes prosecutors. This article challenges the assumption that analysis of the histories of Western intelligence agencies and the study of war crimes trials must be studied as entirely separate and sharply demarcated fields of inquiry; it advocates an interdisciplinary research programme, informed by a series of indepth historical case studies, capable of addressing issues arising from the interaction between these two institutional fields. The proposed research agenda could illuminate aspects of the contemporary role - and future potential of both intelligence agencies and war crimes prosecution bodies. It would investigate tensions between the prosecutors need to employ intelligence agencies to gather trial credible evidence and detain indicted defendants, often by covert and legally questionable means, and the constitutional justifications for holding war crimes trials by reference to the need to reassert the rule of law in the wake of lawless genocide.