In late November 1943 a disabled American president completed a 7,000-mile journey through U-boat waters, a Victorian-era British aristocrat arrived to defend an empire, and a Soviet dictator so afraid of flying that he took an armoured train to Baku and refused a general as his pilot met face to face for the first time. This episode examines why Stalin vetoed Cairo, Baghdad and Basra in favour of jointly occupied Tehran, and how an alleged Nazi plot, Operation Long Jump, was used to move Roosevelt into the wiretapped Soviet embassy, a trap FDR walked into with open eyes to isolate Churchill and win Stalin’s trust.

Inside those walls FDR sided with Stalin against Churchill’s Mediterranean strategy and locked in Operation Overlord for May 1944, trading it for a simultaneous Soviet offensive and a promise to enter the war against Japan. The dinners exposed the fragility of the alliance: the Sword of Stalingrad sliding out of its scabbard, Stalin’s toast to American manufacturing, his proposal to execute 50,000 to 100,000 German officers, Roosevelt’s uncomfortable joke and Churchill storming out. Then came the map: eastern Poland conceded to Stalin, the whole country shifted west into German territory without consulting the Poles, support in Yugoslavia switched to Tito, and FDR asking to keep his fingerprints off the deal to protect Polish-American votes in 1944.

• Why the choice of Tehran and the embassy lodging gave Stalin home-field advantage
• How Roosevelt and Stalin overruled Churchill to commit to the cross-Channel invasion
• The execution toast as a probe of where the Western allies’ moral lines lay
• The secret redrawing of Poland and its link to the American election calendar
• The paradox of proposing the United Nations while carving up sovereign nations behind closed doors