This groundbreaking volume shifts the focus of international relations scholarship to the often-overlooked domestic sources of foreign policy. Through compelling case studies spanning Anglo-American relations to contemporary China's rise, leading scholars examine how internal politics, public opinion, economic interests, and cultural values shape the decisions of major powers.

The book tackles some of the most puzzling questions in international relations: Why did the peaceful Anglo-American transition contradict predictions of inevitable conflict? What can we learn from the formation of domestic cartels and myths of empire from Imperial Germany and Japan to help our understanding of contemporary international relations? What domestic factors drove Putin's dramatic shift from accommodation to confrontation with the West, accounting for his decision to attack Ukraine? How do Japan's internal politics explain its simultaneous economic embrace and strategic opposition to China? How do internal politics also complicate relations between the two sides across the Taiwan Strait and perpetuate their deadlock? Why did Britain and France fail to balance effectively against Nazi Germany despite clear threats, and why did Habsburg Spain decide to take on all perceived challenges to its authority? From the Crimean War to Brexit, from Trump's MAGA movement to Sino-American rivalry, this volume reveals the role of domestic considerations in shaping foreign policy outcomes. The contributors demonstrate that understanding great power behaviour requires looking beyond the international system to the complex political dynamics within states themselves.

It will be essential reading for scholars, policymakers, and anyone seeking to understand the true drivers of international relations in an era of great power competition.