Sunset clauses are a common feature of post 9/11 counterterrorism legislation in western democracies. In this article, I consider the functions and efficacy of these provisions by concentrating on their use in a few notable cases, mainly the United States, Canada, the United Kingdom and India. One way to measure the success of sunsets is to consider whether and how often they actually lead to the expiration or nonrenewal of the statutory provisions to which they are attached. I argue that the utility of sunset clauses should be measured first against the claim that they are an important safeguard against unwise or illiberal legislation, and second as an effective mechanism for promoting democratic deliberation in policy environments governed by panic, fear and an overwhelming sense of urgency.
