This research note addresses the current lack of a comprehensive economic framework for analysing power in international trade. The paper traces the historical understanding of trade dependency from mercantilist doctrines, which focused on the "balance of trade," to modern analyses incorporating concepts like national power, game theory, and international political economy/geoeconomics. It highlights that "critical" trade links are those that could cause significant economic or societal damage, be used for coercion, or threaten national security. The core of the document outlines five categories of methodologies to understand power relations in trade. The conclusions emphasize that in an era of global economic disturbances, understanding trade dependencies and power is crucial.