In May 2013, delegates from over seventy political parties and other organizations gathered in Leipzig to found the Progressive Alliance as an alternative to the Socialist International (SI) created in 1951. Growing unhappiness with the membership of non-democratic and even authoritarian political parties in the SI provided a powerful spur to the new organization. The year before, Sigmar Gabriel, the chairman of the German Social Democratic Party (SPD) and a driving force behind the Progressive Alliance, had withheld his party’s membership dues to the SI, insisting that he would not ‘sit at the same table as criminals’.1 Yet far more was at stake in the Progressive Alliance’s creation than disputes over the Socialist International’s membership. The emergence of the Progressive Alliance constituted a direct challenge to the SI’s version of socialist internationalism, one dominated by party elites, rituals of solidarity, and backroom negotiations producing consensus and non-binding resolutions that were aspirational at best and not programmatic.