The complex relationship between international norms and transational networks of non-state actors is gaining increasing attention in international relations theory. This paper argues that transnational networks of non-state actors gain greater access to and influence over states when they identify with international norms that the states themselves have formally accepted--even if that formal acceptance did not initally reflect any serious intention to implement or monitor the norm in question. This process has been called the 'boomering effect'. The resulting redefinitions of state interests raise the diplomatic salience of the norm in question, and thereby increase its effectiveness. The article illustrates this process with a study of changes in the US foreign policy towards Soviet and Eastern European compliance with the human rights norms of the Helsinki Accords in the mid-late 1970s.