In case of what country's attack was the origins of the Central Powers?
Central Powers The Central Powers (German: "Mittelmächte" ; Hungarian: "Központi hatalmak" ; Turkish: "İttifak Devletleri" or "Bağlaşma Devletleri" ; Bulgarian: Централни сили "Tsentralni sili" ), consisting of Germany, Austria-Hungary , the Ottoman Empire and Bulgaria – hence also known as the Quadruple Alliance (German: "Vierbund" ) – was one of the two main factions during World War I (1914–18). It faced and was defeated by the Allied Powers that had formed around the Triple Entente. The Powers' origin was the alliance of Germany and Austria-Hungary in 1879. The Ottoman Empire and Bulgaria did not join until after World War I had begun, although the Ottoman Empire retained close relations with both Germany and Austria-Hungary since the beginning of the 20th century.
Soviet invasion of Manchuria The Soviet invasion of Manchuria, also known as the Manchurian Strategic Offensive Operation ("Манчжурская стратегическая наступательная операция" , lit. "Manchzhurskaya Strategicheskaya Nastupatelnaya Operaciya") or simply the Manchurian Operation ("Маньчжурская операция"), began on 9 August 1945 with the Soviet invasion of the Japanese puppet state of Manchukuo. It was the last campaign of the Second World War, and the largest of the 1945 Soviet–Japanese War which resumed hostilities between the Union of Soviet Socialist Republics and the Empire of Japan after almost six years of peace. Soviet gains on the continent were Manchukuo, Mengjiang (Inner Mongolia) and northern Korea. The Soviet entry into the war and the defeat of the Kwantung Army was a significant factor in the Japanese government's decision to surrender unconditionally, as it made apparent the Soviet Union would no longer be willing to act as a third party in negotiating an end to hostilities on conditional terms.