Goals such as solidarity or civic fraternization go back to the post-war period, when town twinning formed the vanguard of a nation-state rapprochement. They were seen as small bulwarks against a renewed outbreak of hostilities. The efforts of such partnerships were therefore directed towards cultural exchange and the acceptance of other societies and ways of life. This has led to the development of increasingly diverse forms of cooperation, as Zurich's partnerships with Kunming and San Francisco show.