May 13, 1943 was the end of the war in North Africa. Tehran conference was in November of that year. Roosevelt took the battle ship USS Iowa to Oran and then flew to Tehran. Churchill flew in a modified bomber via North Africa. The Germans never advanced near to the Soviet Iranian border during the war and by November of 1943 were being pushed west by the Red Army. Over the parts of the eastern eastern Atlantic Churchill flew over on his route the allies had air supremacy at the end of 1943. Tehran was the first conference attended by Stalin, Churchill and Roosevelt and none had to traverse high risk space to get there.