Militarization of police forces in the Third Worlds has been prompted by the bureaucracys' self-interest which encourages acquisition of hardware and by the character of contemporary insurgencies threatening a regime. Militarization of police forces has led police to adopt certain military attributes, such as defending the nation from internal and external threats and organizing in large units. Such police depend for their effectiveness on specialized training that is military in orientation and on access to increasingly sophisticated hardware. Military officials are likely to be grateful to an institutional development such as police militarization has had a number of consequences: regimes have an alternative to calling in the army, greater coordination is needed between defense ministry and interior ministry officials, and the police become a rival of the military and political leadership. Militarization is likely to result in increased centralization of military authority. Because police serve to preserve the power distribution, they become more concerned with national policy choices; the militarized police is thus at once useful and worrisome to the Government. Police recruitment efforts are frequently geared to make the applicant reliable police agent and to deter challenges to the existing political structure. However, militarized police units may require a social and ethnic composition different from that of ordinary crime-oriented units. The ethnic composition of the military and the ethnic composition of the regime in power also bear directly on the saliency of ethnicity in police recruitment; police, military, and Government compatibility are assured through ethnic alliance. Notes and 16 references are supplied.