Facing a nuclear rival in a politically unstable region, some nondemocratic states violate the Weapons of Mass Destruction (WMD) nonproliferation treaties, while others of similar size and capacity comply with it. To solve this puzzle, I argue that enduring and effective constraints on authoritarian executives makes compliance more likely, while unconstrained dictatorships will shirk their undertakings. Unlike in democracies, effective constraints in autocracies are determined by the extent of political competition between rivaling factions with divergent economic preferences. The increasing representation of trade preferences among factional veto players increases the likelihood of compliance. I substantiate my claims with statistical analyses which use original data on compliance with WMD treaties. By solving this Middle Eastern compliance conundrum, I contribute a theory that explains compliance decisions for the entire range of authoritarian regime types.
