War, many workers and activists turned to communist parties which grew at the expense of anarchism and other socialist movements. In France and the United States, members of major syndicalist movements such as the General Confederation of Labour and the Industrial Workers of the World left their organisations and joined the Communist International. In the Spanish Civil War of 1936-39, anarchists and syndicalists (CNT and FAI) once again allied themselves with various currents of leftists. A long tradition of Spanish anarchism led to anarchists playing a pivotal role in the war, and particularly in the Spanish Revolution of 1936. In response to the army rebellion, an anarchist-inspired movement of peasants and workers, supported by armed militias, took control of Barcelona and of large areas of rural Spain, where they collectivised the land. The Soviet Union provided some limited assistance at the beginning of the war, but the result was a bitter fight between communists and other leftists in a series of events known as the May Days, as Joseph Stalin asserted Soviet control of the Republican government, ending in another defeat of anarchists at the hands of the communists. Post-WWII By the end of World War II, the anarchist movement had been severely weakened. The 1960s witnessed a revival of anarchism, likely caused by a perceived failure of Marxism–Leninism and tensions built by the Cold War. During this time, anarchism found a presence in other movements critical towards both capitalism and the state such as the anti-nuclear, environmental, and peace movements, the counterculture of the 1960s, and the New Left. It also saw a transition from its previous revolutionary nature to provocative anti-capitalist reformism. Anarchism became associated with punk subculture as exemplified by bands such as Crass and the Sex Pistols. The established feminist tendencies of anarcha-feminism returned with vigour during the second wave of feminism. Black anarchism began to take form at this time and influenced anarchism's move from a Eurocentric demographic. This coincided with its failure to gain traction in Northern Europe and its unprecedented height in Latin America. Around the turn of the 21st century, anarchism grew in popularity and influence within anti-capitalist, anti-war and anti-globalisation movements. Anarchists became known for their involvement in protests against the World Trade Organization (WTO), the Group of Eight and the World Economic Forum. During the protests, ad hoc leaderless anonymous cadres known as black blocs engaged in rioting, property destruction