Voters do not Distinguish Between International Law Regimes: A Survey Experiment on the Relative Authority of International Law and Courts in the Human Rights and Trade Regimes

How far do public responses to international illegality vary depending on the international regime involved and the involvement of an international court? Existing experimental studies have commonly identified a public-support-depressing effect from international illegality but have not examined how this may vary across regimes. This paper addresses that question through a survey experiment examining, across two large anglophone jurisdictions, how far public support for a policy is affected by violation of international laws of the human rights and trade regime respectively, as well as examining how far that effect differs where an international court is involved. We report results suggesting that, while publics care about international illegality, this effect does not vary significantly across international regimes. Rather, it is international illegality tout court that matters. However, the support-depressing effect of international illegality is amplified where an international court has confirmed the relevant legal position. We further report results suggesting that, amongst the various mechanisms by which international law is hypothesised to affect states’ political and moral situations, concerns with promising are most salient in explaining the impact of international illegality on public attitudes.