Beyond the Tricolour explores the history of internationalism through individuals and political organizations who took practical action in defense of internationalist principles.

Birchall looks at committed internationalists who argued against nationalism, racism and war but have too often been neglected by mainstream history. The book focuses on the context of French history, and the French socialist and working-class movement in particular. Beginning from the defense of Dreyfus against anti-Semitism, it covers antimilitarism before 1914, opposition to the First World War, the advent of Communism, then the rise of Stalinism, fraternization with German soldiers during the Nazi occupation, and support for national independence in Indochina and Algeria.