The election of President Barack Obama has generated enormous goodwill abroad. Many have come to anticipate a sharp departure from the foreign policy of President George W. Bush. There is no question that President Obama has broken with his predecessor in important ways, especially in terms of his emphasis on multilateralism and strategic dialogue. Nevertheless, he is unlikely to jettison two core principles associated with what has become known as the Bush Doctrine: state responsibility and anticipatory self-defense. This Note asks whether there is support for these principles under customary international law. It concludes that there is, and that the use of force provisions in the United Nations Charter— at least as originally interpreted in 1945—no longer accurately reflect international legal norms on the use of military force.