In the wake of the cyber-attacks in 2007 against Estonia and in 2010 against Iran, academics have debated the character of cyberwar. This study applies the theories of coercive diplomacy to the cases of Estonia and Iran in order to explain cyber-attacks as instrument for coercive diplomacy. While the long term effects of the attacks have yet to be understood it is clear that cyber-attacks can, and will, become a serious threat against political decision-makers in times of conflict.