Final answer:
The Soviet Union reacted differently to the uprisings in Poland and Hungary due to the levels of threat each posed to Soviet control. In Poland, moderate reforms were tolerated due to their limited nature, while in Hungary, the revolutionary moves to leave the Warsaw Pact led to a heavy military response to reaffirm Soviet dominance.
Step-by-step explanation:
The primary reason that the Soviet Union's reaction to the anti-communist spring in Poland was different than its reaction in Hungary is rooted in the circumstances and the outcomes of the events in these two countries. In Poland, protests eventually led to reforms and a leadership change where Władysław Gomułka, advocating for some level of independence while remaining within the communist framework, was made leader. The situation in Hungary, however, escalated to a full-fledged revolution with the Hungarian government's move to exit the Warsaw Pact, which led to a severe military intervention by the Soviet Union.
During the Polish protests in 1956, there was a distinctly nationalist character calling for changes like the removal of Soviet troops. These led to some concessions without push for Hungary's level of radical departure from Soviet influence. Conversely, in Hungary, the demands quickly evolved into a revolution, with Imre Nagy announcing Hungary's withdrawal from the Warsaw Pact and appealing for Western support, which was a direct threat to Soviet dominance in the region.
The contrast in outcomes reflects the Soviet Union's determination to maintain a tight grip over its satellite states and its willingness to use military force when its control was at risk of being substantially weakened, as was the case in Hungary. However, in Poland where the challenges were more moderate and did not directly threaten the Warsaw Pact or the Soviet Union's hegemony, a less severe response was deemed sufficient.