Between Power and Principle An Integrated Theory of International Law Oona A hathaway in the Chicago lam reriew (20 In March of 2003, as American tanks rolled toward Baghdad, international lawyers in the United States and abroad decried the action as a violation of the United Nations Charter The invasion, some worried, would strip away the last pretense that international law could constrain state action. Others openly questioned whether the increasingly wounded global legal regime was worth saving. If states so openly flouted it, was international law really worth the trouble? The hand-wringing and condemnation were scarcely new. Well before the invasion of Iraq the tide of events had given pause to all but the staunchest believers in international law. Within six short months of entering office, President George w. Bush had withdrawn from the Kyoto global climate accord, threatened to unilaterally abrogate the 1972 Anti Ballistic Missile Treaty, and revoked the U.S. signature on the treaty creating the International Criminal Court. The U.S. president thus looked ready to make good on the promise that Jesse Helms, then-chairman of the Senate Foreign Relations Committee, had made to the UN Security Council only a year earlier to resist any effort to "impose the UNs power and authority over nation states. 2 t Associate Professor, Yale Law SchooL. J D, Yale Law School. I thank the Carnegie Foundation for its generous support of this project through the Carnegie Scholars Program. My thanks also to Craig Estes, Galit Sarfaty, and Alan Schoenfeld for their research assistance and to Ulrich Wagner and especially Alexandra Miltner for their help with compiling and analyzing the datasets used in this Article. I am grateful to Bruce Ackerman, Yochai Benkler, William Bradford, Jutta Brunnee, Steve Charnovitz, Robert Ellickson, Ryan Goodman, Larry Helfer, Rob Howse, Dan Kahan, Alvin Klevorick, Barbara Koremenos Ariel Lavinbuk, Mike Levine, Jonathan R. Macey, Daniel Markovits, Eric Posner, Kal Raustiala, Roberta romano, Scott Shapiro, Peter Shuck, Alan Schwartz, Jim Whitman, Tim Wu, Kenji Yoshino, the faculty of the University of Bremen, and participants in the University of Southern California Conference on Compliance with International Law, the nternational Law Roundtable at Vanderbilt Law School, the Yale World Fellows program, and the University of Toronoto's workshop on international law for helpful conversations about and comments on earlier drafts. Thanks are also due to Gene Coakley and the rest of the staff of the Yale Law School library for their outstanding assistance. Finally i owe the greatest debt to Jacob S Hacker, for his support at every stage of this project. For an interesting discussion that places the decision of the United States to withdraw from the Kyoto Protocol into a broader context by considering the US approach to international environmental law since 1992, see Jutta Brunnee, The United States and International Environmental Law: Living with an Elephant, 15 EJIL 617(200 Senator Jesse Helms, Speech to the United Nations Security Council (an 19, 2000) onlineathttp://www.sovereignty.net/center/helms.htm(visitedNov30,2004)Between Power and Principle: An Integrated Theory of International Law Oona A. Hathaway† Forthcoming in the Chicago Law Review (2005) In March of 2003, as American tanks rolled toward Baghdad, international lawyers in the United States and abroad decried the action as a violation of the United Nations Charter. The invasion, some worried, would strip away the last pretense that international law could constrain state action. Others openly questioned whether the increasingly wounded global legal regime was worth saving. If states so openly flouted it, was international law really worth the trouble? The hand-wringing and condemnation were scarcely new. Well before the invasion of Iraq the tide of events had given pause to all but the staunchest believers in international law. Within six short months of entering office, President George W. Bush had withdrawn from the Kyoto global climate accord,1 threatened to unilaterally abrogate the 1972 Anti￾Ballistic Missile Treaty, and revoked the U.S. signature on the treaty creating the International Criminal Court. The U.S. president thus looked ready to make good on the promise that Jesse Helms, then-chairman of the Senate Foreign Relations Committee, had made to the UN Security Council only a year earlier to resist any effort to “impose the UN’s power and authority over nation states.”2 † Associate Professor, Yale Law School. J.D., Yale Law School. I thank the Carnegie Foundation for its generous support of this project through the Carnegie Scholars Program. My thanks also to Craig Estes, Galit Sarfaty, and Alan Schoenfeld for their research assistance and to Ulrich Wagner and especially Alexandra Miltner for their help with compiling and analyzing the datasets used in this Article. I am grateful to Bruce Ackerman, Yochai Benkler, William Bradford, Jutta Brunnée, Steve Charnovitz, Robert Ellickson, Ryan Goodman, Larry Helfer, Rob Howse, Dan Kahan, Alvin Klevorick, Barbara Koremenos, Ariel Lavinbuk, Mike Levine, Jonathan R. Macey, Daniel Markovits, Eric Posner, Kal Raustiala, Roberta Romano, Scott Shapiro, Peter Shuck, Alan Schwartz, Jim Whitman, Tim Wu, Kenji Yoshino, the faculty of the University of Bremen, and participants in the University of Southern California Conference on Compliance with International Law, the International Law Roundtable at Vanderbilt Law School, the Yale World Fellows program, and the University of Toronoto’s workshop on international law for helpful conversations about and comments on earlier drafts. Thanks are also due to Gene Coakley and the rest of the staff of the Yale Law School library for their outstanding assistance. Finally, I owe the greatest debt to Jacob S. Hacker, for his support at every stage of this project. 1 For an interesting discussion that places the decision of the United States to withdraw from the Kyoto Protocol into a broader context by considering the US approach to international environmental law since 1992, see Jutta Brunnee, The United States and International Environmental Law: Living with an Elephant, 15 EJIL 617 (2004). 2 Senator Jesse Helms, Speech to the United Nations Security Council (Jan 19, 2000), online at http://www.sovereignty.net/center/helms.htm (visited Nov 30, 2004)