In September 2010, a two-judge Second Circuit majority ruled that corporations are immune from liability under the Alien Tort Statute (“ATS”). This statute, which grants aliens access to federal district courts, has emerged as a controversial tool for international norm enforcement in the last thirty years. The unexpected decision to foreclose corporate liability has generated a wave of criticism from human rights activists and international law scholars who claim that the decision is grounded in a fundamental misunderstanding of international law.
This commentary examines the Kiobel decision against other recent interpretations of the ATS, especially those following the Supreme Court’s decision in Sosa v. Alvarez-Machain. Although corporate immunity makes little sense doctrinally, this commentary attempts to provide a rationale for the Second Circuit’s decision. The Kiobel decision was largely the product of policy concerns about expanded use of the ATS. And it stems from the Supreme Court’s mandate to lower federal courts to exercise “vigilant doorkeeping”: narrowing ATS claims to those that arise under “customary international norms.” Confusion over what body of law determines enforcement standards has resulted in varying interpretations of ATS jurisdictional boundaries, and has contributed to the vigorous Second Circuit decision in Kiobel.
Following further consideration among the circuits, the Supreme Court should address whether the ATS allows corporate liability, aiding and abetting liability, and liability for purely extraterritorial suits. Eliminating liability under any of these theories would have resulted in dismissal in Kiobel. However, sweeping rules may screen out meritorious cases. The question then becomes what set of rules would achieve the optimal result, minimizing over-screening while adhering to the Supreme Court’s requirement of caution.
Critics (including the U.S. government) warn that a lack of principled limits will have negative systemic effects, including dire consequences for U.S. foreign policy. However, human rights activists discount these predictions as unfounded and exaggerated. They focus on the ATS’s important role in the development of principles of international accountability, and the importance of granting victims of atrocities access to the U.S. judicial system. As the international enforcement system stands, “[a]dherence to internationally recognized human rights norms remains largely voluntary, and current mechanisms for international enforcement have had little impact on abusive behavior.” ATS litigation provides a unique opportunity for redress for victims of crimes against humanity. However, it remains to be seen whether the benefits of ATS litigation outweigh potential harms to U.S. foreign policy. In articulating the boundaries of ATS jurisdiction, the federal courts must continue to balance the United States’ current international obligations with principles of international comity. The Supreme Court has categorically rejected the imposition of liability that threatens diplomatic relations, and would likely continue to do so in this context. It is unlikely that the Supreme Court would support an ATS claim on a theory of aiding and abetting liability in a purely extraterritorial case when the systemic effects pose great risk to U.S. interests. . . .
 Kiobel v. Royal Dutch Petroleum Co., 621 F.3d 111 (2d Cir. 2010), reh’g en banc denied, No. 06-4800-cv, 2011 WL 338048 (2d Cir. Feb. 4, 2011).
 Sosa v. Alvarez-Machain, 542 U.S. 692, 728, 729 (2004).
 See Terry Collinsworth, The Key Human Rights Challenge: Developing Enforcement Mechanisms, 15 Harv. Hum. Rts. J. 183, 183 (2002).