In case of what country's attack was the origins of the Central Powers?
Dual Alliance (1879) The Dual Alliance was a defensive alliance between Germany and Austria-Hungary, which was created by treaty on 7 October 1879 as part of Bismarck's system of alliances to prevent or limit war. The two powers promised each other support in case of attack by Russia. Also, each state promised benevolent neutrality to the other if one of them was attacked by another European power (generally taken to be France, even more so after the Franco-Russian Alliance of 1894). Germany’s Otto von Bismarck saw the alliance as a way to prevent the isolation of Germany and to preserve peace, as Russia would not wage war against both empires.
Red Army The Workers' and Peasants' Red Army (Russian: Рабоче-крестьянская Красная армия (РККА) , "Raboche-krest'yanskaya Krasnaya armiya (RKKA)", frequently shortened in Russian to Красная aрмия (КА) , "Krasnaya armiya (KA)", in English: Red Army, also in critical literature and folklore of that epoch – Red Horde, Army of Work) was the army and the air force of the Russian Soviet Federative Socialist Republic, and after 1922 the Union of Soviet Socialist Republics. The army was established immediately after the 1917 October Revolution (Red October or Bolshevik Revolution). The Bolsheviks raised an army to oppose the military confederations (especially the various groups collectively known as the White Army) of their adversaries during the Russian Civil War. Beginning in February 1946, the Red Army, along with the Soviet Navy, embodied the main component of the Soviet Armed Forces; taking the official name of "Soviet Army", until its dissolution in December 1991.