Why did Roosevelt support Stalin and not Churchill on the question of opening a second front?

Roosevelt supported Stalin in the question of opening the Second Front in Normandy, and not in the Balkans as Churchill had suggested, because he was striving for the speediest defeat of Germany. And Churchill’s proposal had no military logic, because if the Germans had landed in the Balkans, it would have been easier for them to defend themselves. In addition, Roosevelt was interested in allied countries helping America in the fight against Japan. Stalin declared his readiness to start a war against Japan immediately after the victory over Germany, if the allies recognize the new western borders of the USSR.