1. Introduction

In international taxation countries are keenly jealous of their tax sovereignty: each country pursues dominant strategies (“unilateral tax strategies”), i.e., in game theory terms the strategies that maximize its benefits, no matter what the other countries do. As a result, cooperation becomes difficult because of national interests. My argument instead is the following: not all unilateral tax strategies by individual countries are “egoistic” protecting only national interest because certain of such strategies lead to cooperation if they converge in a multilateral setting. By contrast, unilateral strategies that simply represent national interest without converging in a multilateral setting lead to conflict.

So, it is not the nature of a strategy of being unilateral, but the context in which it plays out, that matters. I will test this argument by sampling two types of unilateral strategies that originated in the U.S.: the global taxation of multinationals of 2021-23 and the executive order April 2, 2025 on “reciprocal tariffs”.