Vereinten Nationen

The provided news articles do not directly mention or relate to the Vereinten Nationen (United Nations). Therefore, it is impossible to provide a summary about the UN based on the given information. The articles discuss an Israeli ambassador criticizing the German President, a dispute over Picasso's "Guernica" painting in Spain, and a discussion about charging entrance fees for the Cologne Cathedral. These topics are unrelated to the UN's activities, structure, or current events involving the organization. Without articles referencing the UN, a meaningful summary cannot be generated.