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.
Holy Alliance The Holy Alliance (German: "Heilige Allianz" ; Russian: Священный союз , "Svyashchennyy soyuz"; also called the Grand Alliance) was a coalition created by the monarchist great powers of Russia, Austria and Prussia. It was created after the ultimate defeat of Napoleon at the behest of Tsar Alexander I of Russia and signed in Paris on 26 September 1815. The intention of the alliance was to restrain liberalism and secularism in Europe in the wake of the devastating French Revolutionary Wars, and the alliance nominally succeeded in this until the Crimean War (1853–1856). Otto von Bismarck managed to reunite the Holy Alliance after the unification of Germany but the alliance again faltered by the 1880s over Austrian and Russian conflicts of interest with regard to the dismemberment of the Ottoman Empire.