This article addresses the absence of the venerable doctrine of good faith interpretation, as well as its companion “liberal interpretation canon,” from modern Supreme Court treaty jurisprudence. Although scholarly accounts suggest that the spirit is still alive, the article demonstrates that the doctrine was silently interred by the Supreme Court early in the last century. From all appearances, the disappearance of good faith from treaty jurisprudence was not by design. Nonetheless, the article demonstrates that even such an unintended drift can have serious negative consequences. In the context of treaty jurisprudence, the consequence of the departure of good faith interpretation has been broad confusion in the lower federal courts over t...