This historical review indicates that the internationalization of police cooperation has made progress whenever the security of the social order seemed to be under threat. The most efficient and effective cooperation has been in the exchange of intelligence on persons, goods, and incidents. Modest agreements on legislative policy and organizational structures have been forced by circumstance rather than planned political choice. In the absence of any imperative to maintain security, the European Community (EC) is not only planning to intensify cooperation but also to harmonize government policies on a wide range of police matters. Based on the experience of cooperation so far in Belgium, The Netherlands, and Luxembourg, EC plans for cooperation are too ambitious. Cooperative efforts should have a limited focus. A primary focus should be on border controls and the harmonization of immigration laws only so far as is necessary to remove primary border controls to the external frontiers. A detailed proposal for the elimination of border controls should be ready by 1992, based on existing cooperation agreements such as those between West Germany and France and between West Germany and Austria.