You were the one making the initial assertion: to apply it to one side but not the other is just double standards.

Had Hungary and Czechoslovakia been de facto parts of the USSR, 1956 and 1968 would never have arisen: that Moscow was reduced to sending in its tanks underlines the limitations of its political fiat. It's for you to explain how Poland got away with its different course: had your claim been valid, that couldn't have happened.

It's also for you to support the claim that in Afghanistan the USSR was "trying to expand its borders". Afghanistan was the last thing Moscow wanted in its territory: it hadn't wanted to go in at all, and only the prospect of a deeply hostile regime on its central Asian border drew it in.

Yours seems a rather absolutist two-dimensional take: intervention = de facto annexation. I invite you again to consider whether this applies to US military actions, and if not, why not?