Tariffs, Global Fragmentation, and the Liberal Order under Trump’s Second Term

This article analyses the tariff strategy of Donald Trump’s second administration, situating it within the broader transformation of U.S. economic governance and its international spillovers. The paper advances three claims. First, tariffs have become the most visible expression of a deliberate turn to unilateralism, both domestically - through an expansive and arguably ultra vires reliance on emergency powers - and internationally - through measures that openly disregard World Trade Organization (WTO) disciplines. Second, Trump’s tariffs embody the “anti-Tinbergen principle”: instead of treating economic instruments as functionally specific, the administration deploys tariffs simultaneously to pursue fiscal, industrial, social, and geopolitical objectives. This multi-purpose use of trade policy blurs boundaries across domains, extending to issues as diverse as migration control, fentanyl flows, and energy deals. Third, and most importantly, tariffs are not merely economic tools. They have become instruments of political reordering that accelerate the fragmentation of the global marketplace and erode the very liberal-democratic principles on which the postwar economic order was built. By weaponizing trade in this way, the United States risks weakening both its own constitutional balance and its long-standing role as architect of the multilateral trading system. Far from delivering the promised revival of American industry and fiscal sustainability, tariffs may produce the opposite outcome: higher costs, weaker alliances, and diminished U.S. leadership in a multipolar trade world.