What did Stalin refuse to do that broke the agreement of the yelta conference?

Stalin refused to hold free elections in Eastern European countries, particularly in Poland, which broke the agreement made at the Yalta Conference to allow democratic processes and self-determination in these nations. Instead, he established pro-Soviet communist regimes, undermining the principles of democracy and contributing to tensions between the Soviet Union and the West. This refusal heightened suspicions and set the stage for the Cold War.