The Chapters in this Part introduce readers to the multifaceted and interconnected governance aspects of tax, trade, and investment regimes. Navigating these regimes, states find themselves contending with conflicting and sometimes mutually exclusive policy choices, necessitating difficult tradeoffs among internal goals as well as between domestic and international goals. The chapters demonstrate that there is very little policy coherence across the global regulatory areas, and that policymakers do not always seem to acknowledge the inconsistency of their own approaches in each area. In some cases, national policy choices respecting cross-border taxation seem to conflict directly with competing national policy goals in cross-border trade and investment. In other cases, national policy choices in one area seem to be constrained by pre-existing international obligations in another. Sometimes, national policy choices seem wholly constrained by historical international ones. When a need for reform in one area arises, multilaterally embedded policy choices in the other areas may interfere if not prevent reform. Each chapter in this Part examines various aspects of these conflicts, with an eye to understanding the legal, social, economic, and distributive aspects of the contemporary tax, trade, and investment landscape.