The article examines the transformation of the regulatory and legal regulation of law enforcement activities of state authorities of the USSR in the extreme conditions of the Great Patriotic War (1941–1945). The purpose of the work is a comprehensive historical and legal analysis of the sources of Soviet law that regulated the organization and implementation of the law enforcement function of the state during the war period. The methodological basis includes dialectical, historical-legal, formal-legal and systemic-structural methods. It is established that under the existential threat constitutional law-making mechanisms were effectively replaced by emergency acts of the State Defense Committee and joint party-state directives with supreme legal force. Trends of militarization of law enforcement procedures, expansion of extrajudicial powers and legalization of analogy in criminal law are revealed. The legitimacy of «party-state» law-making is proved through the prism of functional purpose of acts, and the formal-dogmatic approach to the hierarchy of normative acts is overcome. It is substantiated that law enforcement activities transformed from a mechanism for protecting subjective rights into a tool for ensuring mobilizational stability and national security, which allowed the Soviet state to survive in a total war. The obtained results are of importance for improving modern legislation on martial law regimes.