After the victory of the 1904–5 war, their part in the Great War, and their sizeable participation in the Russian War of Intervention, Japan had without a doubt been left with the impression that she was now a great world power on an equal footing with Great Britain, France, and the USA. When Japan invaded Manchuria in 1931 and occupied the Soviet sphere of influence, the Soviet Union was still not strong enough in the East to oppose the Japanese. By the time of the final engagement in 1939, these combined clashes between the Soviet Union and Japan amounted to over thirty-three thousand Soviet and Mongolian casualties, three hundred and fifty Soviet tanks, and over two hundred Soviet aircraft destroyed.