I don't know your family history, nor will I claim there weren't any innocent people killed by the Red Army. However, the reason the US branch of your family did not have to fight in WW2 is categorically because of the Red Army defeating nazis and not because of any actions by the US government or elites.

Re-read the discussion. It is not about where geographically a white person was less likely to be shot in the 1940s, it is about what it means to be "american". And practically speaking to be "american" is to simultaneously be exploited by capitalists while also perpetuating aggressive war and exploitation on other people, going back all the way to the founding of the country. The promise of better life at different points in time was either fulfilled at other's expense or just a lie.