Why did stalin declare war on japan?

frederick william of brandenburg-prussia trained his son, frederick, to be a hardy soldier. but frederick disliked rifle shooting and horseback riding. unlike his father, he was interested in french literature. he enjoyed poetry and music and, like some others of the enlightenment, he scoffed at religion. his father thought him soft, frivolous and unmindful of his duties. and when frederick refused to put his signature on a right to succession, for a few moments his father strangled him.

the russian revolution of 1917 involved the collapse of an empire under tsar nicholas ii and the rise of marxian socialism under lenin and his bolsheviks.