The study investigated whether increased transatlantic counter-terrorism cooperation has led to increased policy convergence between the counter-terrorism policies of the EU and US. Theory suggests that when transnational communication increases, so should policy convergence. The study conducts a comparative qualitative content analysis of EU and US counter-terrorism policy documents in the time period between 9/11 and 2006. The focus is on the description of terrorism and terrorists as a threat and suggested counter-terrorism measures. A short comparative analysis is also conducted on the counter-terrorism cultures of Europe and the US to aid in establishing whether cultural similarity has facilitated the effectiveness the causal factor. The analysis shows that EU and US counter-terrorism polices mostly exhibit fluctuations in convergence of different policy aspects, with a low degree of enduring convergence and key differences persisting. Some of these differences appear to be attributable to the divergence in the counter-terrorism cultures in Europe and the US. The study concludes is that conversely to what theory suggests, communication as a causal factor does not appear to be sufficient in itself to cause increased policy convergence, and that the causal factor lacks effect without a corresponding facilitating factor.