This text is an examination of the evolution of the national security policies of the countries of East-Central Europe - Poland, the Czech Republic, Slovakia and Hungary - since the East European revolutions of 1989. It also analyzes the Visegrad group regional co-operation process between the East-Central European states, their relations with the main European security institutions (the European Union, NATO and the conference on security and co-operation in Europe) and their position in the European security order of the 1990s.