Combining insights from historical analysis with the collective-action school of political sociology, Cyrus Zirakzadeh argues that there was a calculative, instrumental dimension to the behaviour of the Basque revolutionary group, ETA, that scholars too often neglect. This work elaborates on the social and economic concerns of members of ETA and the Basque Nationalist Party, recounts debates within ETA over the political effectiveness of armed struggle, and discusses the influence of local social movements and nationalist and non-nationalist ideologies on etarras' (ETA members) thinking.