The Altmark affair

In February 1940, a German supply ship, the Altmark, was bringing back to Germany, through the coastal waters of neutral Norway, nearly 300 British prisoners captured by the battleship Graf Spee. Spotted, it took refuge in a Norwegian fjord, under the theoretical protection of Oslo's neutrality, which Norwegian ships were enforcing.

The commander of the destroyer HMS Cossack had to decide. To board the Altmark in Norwegian waters to free the prisoners, violating Norway's neutrality and risking a diplomatic incident. To respect Norwegian neutrality and let the ship slip away with its prisoners. Or to block the Altmark without boarding it, while awaiting instructions.

The stakes went beyond the fate of the prisoners: it was the question of respect for neutral waters in time of war, and the risk of precipitating a crisis in Scandinavia — a region the British and the Germans already coveted (Swedish iron, Narvik). Churchill, at the Admiralty, was following the affair closely.