This course is an introduction to the law and policy of U.S. taxation of U.S. and foreign persons engaged in cross-border activities. The course will address both how individual and corporate foreign taxpayers are taxed by the United States, and how U.S. individual and corporate taxpayers are taxed by the United States on income earned in or from other countries. Topics will include U.S. jurisdiction to tax, allocation of income, withholding taxes, the foreign tax credit, deferral, transfer pricing, and tax treaties. The course will also consider how the U.S. rules in these areas are influenced by developments in other countries. The goal of the course is to provide an overview of the relevant law and policy considerations, with a focus on specific issues that are presently contested as a policy matter. Students should leave the course with an understanding of the basic framework for U.S. international tax law and a sense of some of the policy debates surrounding the current rules.