No doubt that all of Britain, the Soviet Union and communists everywhere wanted the US to enter the war against the German juggernaut that threatened both Russia and Britain. No doubt Britain had cracked the Japanese code, knew that Pearl Harbor would be attacked, and withheld the information. The Soviets had penetrated the Roosevelt administration and used every overt and covert ruse to get the US involved against Germany. Still the Soviets feared a two front war. If the Japanese attacked, the Soviets would have been very hard pressed. They were probably astonished that Hitler declared war on the US and did not get a commitment from Japan to attack the Soviet Union.
Yeah, the russkies had already experienced the jap navy at Port Arthur (the Tsar’s navy destroyed). Always important to realize the russians are really orientals, despite the great russians resemblance to Westerners.
Doubt the Japanese wanted anything to do with a war with the Soviets. The Soviets in August 1939 inflicted a major defeat on the Japanese army along the Mongolian border at Khalkhin Gol. General Zhukov made mince meat out the Japanese. The Japanese planned to counterattack, but before that operation could begin, Tokyo signed an armistice with Moscow. Until August 1945, when Marshal Rokossvasky launched his assault against the Japanese in the far East, the Japanese were quite willing to leave the Soviets alone. This even though they (the Japanese) knew that most of the Soviet troops in the far East had been sent to the West to fight the German.