In "The Most Dangerous Game," if Zaroff represents Russia and Rainsford represents America, how is the outcome and aftermath of WWI represented in these characters?
This is a very interesting question to think about. In some ways, you might want to ask this question about the aftermath of the Second World War as well as the first. However, if we focus on World War One, we can identify the following parallels.
There does seem to be a deliberate link by the author to link Zaroff in with a dying aristocratic class-based age. Note how he is introduced to us and to Rainsford:
He had high cheekbones, a sharp-cut nose, a spare, dark face, the face of a man used to giving orders, the face of an aristocrat.
The use of the word "aristocrat" is very important, as it conjures up images of Russia pre-1918 and the Revolution, which swept away feudal society and replaced it with Communism. I suppose this is one of the major parallels we can identify. In the aftermath of WWII, Russia as it had been known ceased to exist, just as Zaroff himself, so secure and arrogant in his position of power, ceased to exist.
Similarly, perhaps we can read into the triumph of Rainsford the rise in power and prestige of the United States of America and the eventual victory of capitalism as a world-leading ideology. Of course, where the analogy falls down is that the USA and Russia were actually on the same side during the war, rather than opposing each other, which perhaps makes this question more relevant when considering WWII.