When the First World War ended, it left old empires crumbling across Central Europe, Asia and the Middle East. In the aftermath national movements contested for independence and Communists fought for influence over newly mobilised layers.

The Comintern's Second Congress in 1920 had debated the national question in the age of imperialism and had generally resolved that Communists should support national movements while maintaining revolutionary and working-class independence. Yet balancing these priorities in practice was proving difficult and, in some cases, deadly for Communists.

At the Fourth Congress, delegates weighed up the record of colonial revolts in the years since 1920 and attempted to formulate an "anti-imperialist united front" approach that could guide Communist strategy going forward.