Germany's second unification in the modern age proceeded in a completely different way from the first, particularly in terms of security policy. The creation of the German Reich under Prussian leadership in 1871 was the result of three wars. Establishment of the Reich was pushed through unilaterally, that is, without the agreement and to some extent against the will of the other members of the European system of states. The second German unification proved truly different. It was peaceful through and through, and even the collapse of the German Democratic Republic (GDR) did not cost a single human life. Unification took place not against the will of the members of the European system of states most affected by the change, but with their active participation and consent. It was the result of what was probably the most intensive process of bilateral and multilateral diplomacy of this century.

More significantly, the two unifications differed vastly in terms of their consequences for security in Europe. The foundation of the Reich laid the basis for what would become known as the “German question.” It created a state that had a larger population than any other state in Europe with the exception of Russia and posed a problem for the stability of the European system of states because of its particular social and industrial dynamics. Its internal structure represented the other side of the German question. For the surrounding world, a united Germany with an authoritarian or nondemocratic regime represented a threat and, indeed, twice either carried coresponsibility for or triggered off a catastrophe. Thus the problem of German unity and a democratic structure became a question of European significance and a central problem for European security.