It was different because the Soviet policies, while they could get ugly and result in some injustices, were generally done to protect the USSR itself. Russia's geography is such that the only realistic route for an invasion is through Poland, Ukraine, etc. This is the route that Germany had twice invaded and nearly destroyed Russia. For that reason the Soviets (and even contemporary Russia) considered maintaining a buffer in Eastern Europe to be critical to their security. Not to mention that by and large they didn't economically exploit these states, but in fact spent a whole lot of money rebuilding and rearming them. This is all in contrast to the US who would regularly overthrow elected governments not for the purposes of protecting their own borders but for encircling the Soviets. Consider some of the American and British interventions (coups and invasions): Korea, Iran, Vietnam, Indonesia, Greece. Are any of these close to the US? No, but they're all pretty close to the USSR. Compare that to the four major Soviet interventions: GDR, Hungary, Czechoslovakia, and Afghanistan. All states which were in the immediate vicinity of the Soviet Union. Not to mention that US interventions often took place in the context of a state trying to free itself from Western exploitation, even if that state posed no threat to the US like Chile, Guatemala, Nicaragua, or the Congo. In these cases and others I mentioned, American corporations stood to lose billions if the elected governments got their way. In other words the Soviet policies were driven by a need to protect themselves after being nearly destroyed. The American policies were motivated by a desire to strangle the USSR and from pure unadulterated greed.