In the ongoing crisis in, and of, the eurozone, the fates of trade unions in different countries are more than ever linked to each other, while the respective national areas of conflict are drifting apart. Most notably, the damage caused by the widely hailed German labour market 'reforms' before the crisis, which have resulted in a substantial decline in the impact of trade union policy in Germany, has in the course of the eurozone crisis become a threat for unions at the 'periphery'. This article argues that, while unions in individual countries will necessarily continue to fight the dominant EU crisis management policies primarily at national level, their prospects of success will increasingly depend on their transnational cooperation. The argument is developed through a comparison between the problems faced by trade unions in Greece and Spain on the one hand, and in Germany on the other.