In the case of Poland, though, the post-war situation had more to do with Stalin wanting to punish Poland for interfering in Ukraine, as well as put more distance between the core of the Soviet Union and Germany, by seizing Polish territory in the east to give to the Ukrainian SSR, but in exchange and to weaken Germany, most of Prussia in Germany was seized and given to Poland, with the attending population transfers. In any case, with the Warsaw Pact, any revanchist sentiments that may have remained in Poland weren't going to get off the ground.

Stalin forcibly moved millions of Poles and decreased Polish territory by 1/7th, that after hundreds of thousands of Poles were murdered by Ukrainians and 2 out of top 5 pre-WW2 Polish cities become Ukrainian/Lithuanian capitals.

Poles behaved very responsibly after 1989. Let's remember Poland got independent in 1989 and Ukraine/Belarus/Lithuania in 1991. There was a window of a year or so in which Poland had already organised state and army and the eastern neighbors - didn't.

It could have gone very wrong (think - Yugoslavia like) if not for the 30 years of internal discussions about the imperialism and future reconcilliation among Polish oppositional elites.