Why did Stalin believe a second front was delayed?

Stalin believed that the delay in opening a second front in Europe during World War II was primarily due to the Western Allies' reluctance to engage fully against Nazi Germany. He suspected that the Allies, particularly the United States and Britain, were intentionally prolonging the conflict to weaken the Soviet Union and reduce its influence in post-war Europe. This perception fueled distrust between the Soviet Union and the Western powers and highlighted the differing strategic priorities among the Allies.