History of Germany during World War I
In November 1918, with internal revolution, a stalemated war, Bulgaria and the Ottoman Empire suing for peace, Austria-Hungary falling apart from multiple ethnic tensions, and pressure from the German high command, the Kaiser and all German ruling princes abdicated. On 9 November 1918, the Social Democrat Philipp Scheidemann proclaimed a Republic, in cooperation with the business and middle classes, not the revolting workers. The new government led by the German Social Democrats called for and received an armistice on 11 November 1918; in practice it was a surrender, and the Allies kept up the food blockade to guarantee an upper hand. The war was over; the history books closed on the German Empire. It was succeeded by the democratic, yet flawed, Weimar Republic.
West Germany
Following the collapse of communism in Central and Eastern Europe in 1989, symbolised by the opening of the Berlin Wall, there was a rapid move towards German reunification. East Germany voted to dissolve itself and accede to the Federal Republic in 1990. Its five post-war states () were reconstituted along with the reunited Berlin, which ended its special status and formed an additional . They formally joined the Federal Republic on 3 October 1990, raising the number of states from 10 to 16, ending the division of Germany. The expanded Federal Republic retained West Germany's political culture and continued its existing memberships in international organisations, as well as its Western foreign policy alignment and affiliation to Western alliances like UN, NATO, OECD and the European Union.