when did the soviet union declared war on japan
Soviet–Japanese War The Japanese were caught completely by surprise when the Soviets declared war an hour before midnight on 8 August 1945, and invaded simultaneously on three fronts just after midnight on 9 August.
Russo-Japanese War Russia suffered multiple defeats by Japan, but Tsar Nicholas II was convinced that Russia would win and chose to remain engaged in the war; at first, to await the outcomes of certain naval battles, and later to preserve the dignity of Russia by averting a "humiliating peace". The war concluded with the Treaty of Portsmouth, mediated by US President Theodore Roosevelt. The complete victory of the Japanese military surprised world observers. The consequences transformed the balance of power in East Asia, resulting in a reassessment of Japan's recent entry onto the world stage. It was the first major military victory in the modern era of an Asian power over a European one. Scholars continue to debate the historical significance of the war.