In this comparative qualitative study, the authors examine how local bargaining shapes the trade-off between labor flexibility and employment security policies in four multinational subsidiaries in Belgium, Britain, and Germany. They also consider whether and how union power to shape flexibility and security policies is affected by national institutions, the way that multinationals organize their subsidiaries, and local contextual factors. Findings support this multilevel, interdependent framework. Trade-offs are shaped by differences in workers' structural power in specific local subsidiaries. Differences in inter-subsidiary organizational configurations, markets, and technologies modify how unions can leverage collective resources to wield power in their relationship with management.