This paper investigates states' commitment to human rights, democracy and rule of law through ratifying Council of Europe treaties. We present a first comprehensive analysis of ratifications of all 221 Council of Europe treaties that opened for ratification since 1949 among the 47 current member states. Applying a multilevel Cox regression, we observe a strong influence of external sources for states' commitment and find evidence for both coercion and emulation mechanisms. First, upcoming EU membership is strongly and positively associated with treaty ratification, corroborating the relevance of accession conditionality in making countries to commit to human rights and democracy. Second, states are much more likely to ratify if a neighbouring country has ratified at the same time, which confirms a strong pattern of regional diffusion of rights acceptance in Europe. However, we find that this pattern of regional diffusion is stronger among states with lower levels of democracy, suggesting that emulation proceeds through mimicry. Finally, our analysis shows that Council of Europe treaty ratification is especially strong during the first years after treaty opening, suggesting that ratification reflects concerted efforts by states involved in the negotiation of regional treaties.