AbstractThe dependency relationship in economic and trade cooperation between countries has long been a subject of ongoing debate among scholars of international relations. Albert Hirschman proposed his theory, known as the “Hirschman effect,” which examines how profit‐making groups influence the foreign policies of nations. However, this article contends that interest groups alone cannot fully account for the Hirschman effect. Through examining cases involving Southeast Asian countries and China, it becomes evident that security needs and interest preferences collectively influence the strength of the Hirschman effect between small and large countries. Specifically, Cambodia, Malaysia, and the Philippines illustrate varying degrees of the Hirschman effect, with Cambodia exhibiting a positive effect, Malaysia demonstrating a composite effect, and the Philippines displaying a negative effect.