This article studies the contestation of liberal-democratic norms from within the liberal international order (LIO), focusing on the case of abortion rights. The US Supreme Court’s decisions on abortion, central to both domestic and global debates, provide a compelling case study of how two opposing sides may invoke the same norms, rather than presenting a case of norm collision or co-optation. In contrast to the binary pro-choice versus anti-abortionist framing, this article shows that both sides invoke liberal-democratic norms, but differ in how they relate the norms to each other and how they interrupt established norm relations. Against this background, the article introduces the concept of norm decoupling, highlighting how norm entrepreneurs isolate certain norms from hitherto related norms. This process contributes to a more subtle backsliding of the LIO, particularly by decoupling majority votes from other democratic, substantial norms, and by decoupling liberal-democratic norms from their gendered dimensions. Norm decoupling thus explains diverging interpretations of shared norms within the same context. This advances our understanding of norm contestation and interpretation, shedding light on how liberal-democratic norms subtly erode from within the LIO.