This chapter proposes that general international law imposes on the signatories to a treaty the obligation not to defeat the object and suggests that treaty prior to its entry into force. Decisional law, state practice, and the Vienna Convention on the Law of Treaties all support this proposition. The obligation has a firm theoretical basis in the general principle of abuse of rights. The legal effect of signed but unratified treaties has been considered in a number of international court and arbitral decisions. While some commentators regard this line of decisions as establishing a legal obligation not to defeat the object or purpose of the treaty prior to its entry into force, others regard it as inconclusive at best. Numerous treaties have included provisions placing obligations on the signatories prior to entry into force. The chapter concludes with a discussion of the content of the obligation and attempts to discern its contours and extent.