This study tackles the question to what extent the composition of protest events is determined by the stance of governments. Established contextual theories do not formulate propositions on how context affects individual protesters. The article engages in empirically testing whether the macro-context affects the internal diversity of the crowds that took to the streets on Feb. 15, 2003, the massive day of protest against the upcoming war on Iraq. Drawing on a survey of 6,753 individual demonstrators in eight countries, we find that the composition of the marches is determined by the stance of the government and the opposition in the countries at stake. Apart from government stance, also the support in public opinion and the type of mobilization (media support) matter for internal diversity. (Contains 10 tables, 2 figures, and 7 notes.)