This thesis analyses five principal impediments to the exercise of adjudicatory jurisdiction over international crimes, namely: 1) Amnesties, 2) Pardons, 3) Statutes of limitation, 4) Immunities, and 5) the principle of "Ne Bis In Idem". It examines the historical and contextual background and policy justifications of each impediment, and assesses the legal arguments used to reject the application of such barriers to prosecution when used in cases dealing with international crimes (identified as war crimes, crimes against humanity, genocide and torture). The thesis proposes that approach based upon an "interests analysis", derived from policy oriented approaches to international law, provides a reasonable, coherent and transparent means for courts to resolve the question of jurisdiction when faced with competing rules or principles such as those under review