A strong criminal justice response, supported by the core principles of international law and human rights standards, remains the crucial tool in the global efforts to fight the scourge of terrorism. Several elements of international law are directly applicable to strengthen this tool. This paper examines three: first, the obligation to prohibit and criminalize terrorist offences in domestic criminal legal orders; second, obligations aimed at strengthening prevention and repression of terrorism; and third, the framework and tools for international cooperation in prevention of terrorist acts and in prosecution and punishment of the perpetrators.