Technically yes, it is true that Germany was separated into two nations following World War II, although "nation" would be the wrong word, since there instead was "East" and "West" Germany, with the former being controlled by the USSR and the latter being controlled by the Allies.
Rome becomes a republic. It became a republic in 509 BC, Julius Ceasar is assassinated in 44 BC, and Rome becomes an empire when Augustus takes power in 27 BC.
It was A. Austria that Otto von Bismarck took control of in order to start a war in 1866 to gain control of German-speaking states. This is an example of nationalism and imperialism.