I argue, contrary to standard claims, that accomplice liability need not be a causal relation. One can be an accomplice to another’s crime without causally contributing to the criminal act of the principal. This is because the acts of aid and encouragement that constitute the basis for accomplice liability typically occur in contexts of under- and over-determination, where causal analysis is confounded. While causation is relevant to justifying accomplice liability in general, only potential causation is necessary in particular cases. I (...) develop this argument through the example of the role of U.S. legal officials in abetting the acts of unlawful interrogation that have taken place since 2001. I also suggest that there may be a limited justification for ex post ratificatory accomplice liability. (shrink)