On July 3, 1940, the Royal Navy killed 1,297 French sailors in under 20 minutes, and the victims were Britain’s allies of just weeks earlier. This episode reconstructs the desperate strategic math behind Operation Catapult: France had fallen, the French Navy was the second-largest capital-ship force in Europe, and the British War Cabinet judged Hitler’s Article 8 promise and Admiral Darlan’s word to scuttle insufficient against the risk that the fleet might fall to the Axis.

We cover the bloodless seizures in Plymouth and Portsmouth, the fatal scuffle aboard the submarine Surcouf, the peaceful negotiation at Alexandria, and the catastrophe at Mers-el-Kebir. Admiral Gensoul refused to receive Captain Holland because of his rank, then sent a truncated summary of the British ultimatum to his government that omitted the option of sailing to the French West Indies. Moored stern-out with their main guns pointed at the shore, the Dunkerque and Strasbourg could not return fire effectively. The Bretagne exploded with 977 men aboard; Strasbourg escaped to Toulon, where in November 1942 the French scuttled 77 ships rather than surrender them to the Germans, just as Darlan had promised.

• Why the British War Cabinet could not afford to blockade French ports and wait
• The four options in the ultimatum and the one that never reached Vichy
• How harbor geometry turned modern battleships into sitting targets
• Vichy’s severed relations and reprisal raids on Gibraltar
• The historians’ debate: ruthless proof of resolve or self-defeating tactical failure