Adenauer ensured a generally free and democratic society, except the banning of the communist party and the BND spying on SPD on behalf of the CDU (see #Intelligence services and spying), and laid the groundwork for Germany to reenter the community of nations and to evolve as a dependable member of the Western world. It can be argued that because of Adenauer's policies, a later reunification of both German states was possible, and unified Germany has remained a solid partner in the European Union and NATO. The British historian Frederick Taylor argued that in many ways the Adenauer era was a transition period in values and viewpoints from the authoritarianism that characterized Germany in the first half of the 20th century to the more democratic values that characterized the western half Germany in the second half of the 20th century.