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.
Dual power (Russian Revolution) "Dual Power" (Russian: Двоевластие , "Dvoyevlastiye" ) was a term first used by Vladimir Lenin, although conceptually first outlined by Pierre-Joseph Proudhon, which described a situation in the wake of the February Revolution in which two powers, the workers councils (or Soviets, particularly the Petrograd Soviet) and the official state apparatus of the Provisional Government coexisted with each other and competed for legitimacy. Lenin argued that this essentially unstable situation constituted a unique opportunity for the Soviets to seize power by smashing the Provisional Government and establishing themselves as the basis of a new form of state power. This notion has informed the strategies of subsequent communist-led revolutions, including the Chinese Revolution led by Mao.