Recent scholarship argues that even weak international organizations can influence state behavior by affecting information and accountability politics. A prominent national in a leadership position increases such leverage. This can be exploited by scholars interested in estimating whether international organizations have an independent effect on state behavior, especially when the selection of high-level officials occurs through an observable process such as rotation or competitive elections. I illustrate this point with an analysis of whether having a national elected as permanent judge increases cooperation with the International Criminal Court (ICC). Judges were chosen through competitive elections. I use a regression discontinuity design to obtain valid causal estimates; essentially comparing states that just did and just did not have a national elected as judge. The results show that states with nationals as permanent judges were less likely to undermine the ICC by signing non-surrender agreements with the United States and more likely to adopt a broad range of legislative measures that integrate the Rome Statute and cooperation with the Court into domestic law. This suggests that even indirect institutional participation that confers no meaningful influence can have meaningful behavioral effects.