While the Model Penal Code was certainly one of the most influential developments in criminal law in the past century, the American Law Institute (ALI) took a seriously wrong turn by recognizing “renunciation” as a defense to the crime of conspiracy. Under the Model Penal Code formulation, a member of a conspiracy who later disavows the agreement and thwarts its objective (for example, by notifying authorities of the planned crime in order to prevent its completion) is afforded a complete defense to conspiracy liability. This defense has enormous implications for crimes involving national security and terrorism, which are typically planned covertly and involve extensive coordination among multiple actors.