Drawing on the Counter-Terrorism Strategic Communication (CTSC) Project’s research paper A Brief History of Propaganda during Conflict, this Policy Brief lays out the key policy-relevant lessons for developing effective counter-terrorism strategic communications. It presents a framework of interrelated macro-, mezzo- and micro-level considerations for maximizing the efficacy of not just a strategic communications campaign but message design. Historical examples are drawn upon to illustrate their practical application. The Policy Brief concludes by analysing four key strategic-policy principles arguing that a counter-terrorism strategic communications campaign is more likely to be successful if it is based on the cumulative effects of a multidimensional messaging strategy.