This paper explores the application of Article 10 of the European Convention on Human Rights, which guarantees the right to freedom of expression, in the context of criminal proceedings arising from non-violent direct action by protesters against nuclear weapons. It does so with reference to the International Court of Justice's advisory opinion in the Nuclear Weapons Case, Strasbourg case law, and domestic cases in which individuals were prosecuted for causing damage at military bases. It argues that since the rule of law is a fundamental principle of a democratic society, interference by a State with the exercise of the right to freedom of expression cannot be 'necessary in a democratic society' for the purposes of Article 10(2) unless it is shown to be consistent with the State's obligations under international law. It also reveals the potentially powerful interaction of national law, international law, and the European Convention. This is particularly important in the light of recent remarks about the limits of self-help and civil disobedience.