German Empire
The high command under Paul von Hindenburg and Erich Ludendorff increasingly controlled the country, but in October after the failed offensive in spring 1918, the German armies were in retreat, allies Austria-Hungary and the Ottoman Empire had collapsed, and Bulgaria had surrendered. The Empire collapsed in the November 1918 Revolution with the abdications of its monarchs. This left a postwar federal republic and a devastated and unsatisfied populace, which later led to the rise of Adolf Hitler and Nazism.
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.