The Forgotten Appeasement of 1920 examines a turning point in East European history: the summer of 1920, when Lenin’s Soviet Russia decided to challenge the Versailles system and launch a military attack on the continent. The outcome of this attack might have been the occupation of all of Poland and East Central Europe, and a Red Army sweep further west. This book probes the British–Soviet negotiations and diplomatic operations behind the scenes. Professor Nowak uses hitherto unexamined documents from Russian and British archives to show how (and why) top British politicians were ready to accept a new Russian imperial control over the whole of Eastern Europe. Nowak unravels this previously untold story of that first and forgotten appeasement, stopped only by the Polish military victory over the Red Army. His excellent historical craftsmanship and new sources contribute to the book’s quality, filling up a lacuna in contemporary historiography. This book will appeal to researchers of geopolitical affairs and the Great Powers, the history of Poland, and the political mentality of Western elites. It will also be of interest to university students and tutors, scholars of history and international relations and – thanks to the book’s brisk and fascinating narrative – amateur historians and history aficionados.