The ethnic conflict in the region has been one of the most intractable political problems facing Spain since the end of the Franco dictatorship in 1975. The policing of ethnically divided societies raises issues about the composition of the police and its ability to treat minority members impartially. This problem is exacerbated when the ethnic minority supports terrorist organizations which engender high degrees of popular support. The article considers the background to the Basque conflict. It examines the evolution of the national terrorist group ETA, the problems of policing and counterinsurgency, and issues of international counterterrorist cooperation. Finally, the author discusses problems raised by the Spanish government's policy of trying to reintegrate terrorist groups into the democratic process. 33 references