Following the rising popularity of nationalist parties in Western democracies, international institutions have witnessed an increase in animosities and withdrawals. Brexit arguably marks the most significant instance of this phenomenon to date. A growing literature examines the origins of nationalist successes such as the Brexit vote and explores if similar economic, social, and political conditions could fuel equivalent disintegration processes elsewhere. However, less is known about the extent to which such withdrawal episodes themselves affect nationalist demands for reducing their countries’ international commitments in other countries. In this paper, we argue that large-scale disintegration episodes such as Brexit provide new information about the feasibility and desirability of nationalist policies. Hence, these episodes are likely to affect partisan discourse about similar nationalist projects in other countries: Depending on the success of such precedents, nationalists abroad will either be encouraged or deterred to follow a similar disintegration path. Thus, we expect nationalists in other countries to learn from these precedents. We explore this argument based on a quantitative text analyses of media reports in selected European countries. Our results show that nationalists in Europe significantly moderated their demands as the Brexit-drama unfolded, especially as the difficulties associated with leaving the EU became increasingly obvious. This suggests that Brexit indeed provides a reality check for nationalist pro-Leave arguments. We discuss the implications of our findings for Western democracies and international institutions more generally.