Some of the problems a border-free Europe will present to its police forces are briefly discussed while emphasizing the value of international police cooperation. The prospect of a border-free internal market within Europe is a matter of great interest to European police executives. Border-free cooperation presents a chance to effectively counter international crime such as terrorism, drug trafficking and organized crime. The main challenges facing police in Europe after 1992 are the implications for national security in terms of the free movement of people, drugs, terrorism, and organized crime. Systematic controls will be carried out only at external frontiers, which will only be as strong as their weakest link. Once inside a country, a person can move at will across internal frontiers, which means across jurisdictions of control. One possible alternative is to differentiate between European Community citizens and third country citizens in the checks done at the various borders. International police cooperation is viewed as crucial to the ability to plan for the policing efforts in 1993 and beyond.