This chapter addresses the legal framework used by the plaintiffs to seek accountability and the evolving jurisprudence under the Alien Tort Statute (ATS); the current status of civil corporate liability for international law violations in US courts; and the particular defenses raised by the contractors to avoid liability, including the government contractor defense, battlefield preemption, derivative immunity and the political question doctrine. Notably, the doctrines or principles relied upon by courts to block adjudication are more often grounded in prudential concerns related to domestic enforcement of international law – arguably an expression of a conservative strand of ‘judicial activism’ – rather than a normative bar to corporate liability. As part of this assessment, the chapter surfaces some of the issues relevant to negotiations of an international treaty applicable to transnational business entities, including the threshold question of corporate liability for international law violations and extra-territorial jurisdiction, and comments on certain ‘soft law’ mechanisms that have emerged in response to the rising use of private military and security contractors.