Regional governance has been reinforced or introduced in most countries of western Europe since the 1970s, and the European Community has developed its own strategy of European integration, fostering new trans-European regions of common economic and social interests, each comprising old regions from several nations. In eastern Europe, 40 years or more of authoritarian centralist governments failed to quell regionalist forces, which brought violent resurgences of ethnic regionalism after the political upsets of 1989.