Migration diplomacy in Mexico–United States relations: Decision-making under asymmetric structures

Abstract Research on migration diplomacy has shown that control over cross-border mobility can function as a power resource, enabling transit states to extract concessions from destination countries. However, transit states do not systematically activate this potential leverage, nor do they uniformly engage in rent-seeking behaviour. This article asks why transit countries occupying similarly advantageous geopolitical positions adopt divergent approaches to the use of migration power. Focusing on Mexico–United States relations during Donald Trump’s first presidency, it shows that Mexico initially refrained from instrumentalising migration control and later relied on defensive rather than extractive uses of its leverage. To explain this variation, the article develops an analytical framework that conceptualises transit states’ choices regarding the activation of migration power as strategic decision-making grounded in cost–benefit calculations under specific structural constraints. It shows that these evaluations are context-dependent and shaped by how actors perceive their scope of action. The framework examines how political, reputational, and implementation costs shape states’ willingness to deploy migration leverage and how different aims – punitive, extractive, defensive, and deterrent – structure its use in practice. By shifting attention from rent-seeking behaviour to strategic restraint and defensive action, the article broadens the explanatory scope of the migration diplomacy literature.