In 1990, Germany was reunited. The new Federal republic of Germany (FRG) became a member state of the EC and the NATO. This event was the final achievement of the “Westintegration” of the whole Germany. In fact, it was the highest goal of the former FRG, West Germany, which was an original member of the European integration and which had gained membership in the NATO in 1955. This article deals with “Westintegration” of the (former) FRG under the Chancellor Konrad Adenauer in relation to the German unification. It examines how and why Adenauer tried to integrate the FRG into the “Euro-Atlantic Community” during the crucial years, 1953-1955. “Westintegration” and the German unification were not antinomy to each other. All the following Political aims had to be achieved in the liberal democratic Western World: the European integration, the membership in the NATO, and the German unification. In other words, “Westintegration” needed to be compatible with the German unification, and “Westintegration” of the whole Germany had to be accomplished. In this regards, the European Defense Community (EDC) project was the most important but just a first step to integrate Germany into “Euro-Atlantic Community” and to recover its sovereignty in the free world. Why was the EDC important? Adenauer disliked the military framework of the EDC. However he needed EDC because this project contained the further plans to make the political integration (EPC). Moreover, EDC membership had to lead NATO membership in his recognition. European integration and Western alliance were inseparable basis of “Euro-Atlantic Community”. “Only in ‘Euro-Atlantic Community’, economic wealth, political stability, military security, and ideal unification will be achieved”. This “Confession of faith” was the main justification to adhere to EDC and to gain broad public support to Adenauer's foreign policy, “Politik der Stärke” (“Policy of Power”). In 1953, Adenauer reacted against the detente policy of post-Stalin Soviet government and behaved negatively to the Allied Four Power talks proposed by Churchill's Britain. For Adenauer who desired the realization of the EDC, the final failure of the EDC in August 1954 wasa terrible misfortune. Nevertheless in 1955, the FRG could gain membership in the NATO and welcomed new integration plan in Messina. These events of 1955 were just half, but precious steps of German integration into the “Euro-Atlantic Community”.