Randomizer

The precident for sinking ships involved in saving life goes back to the first days of submarine warfare and it was the German Navy that established it.

On 20 September 1914 U-9 (KK Otto Weddigen) torpedoed the Cressy Class armoured cruiser HMS Aboukir off the Dutch coast. Aboukir's accompanying sisters HMS Hogue and HMS Cressy stopped to rescue Aboukir's crew believing she had struck a mine. Weddigen then torpedoed Hogue and Cressy in quick succession, most of Cressy's crew were killed since all of her boats and rafts were already in the water. Over 1400 British sailors were killed, many young reservists and new recruits.

Would Hartenstein have started rescue operations had Laconia not been carrying Italian POW's? Not likely by most accounts but that is purely speculative. We do know that before the Laconia incident his actions towards survivors were typical of the older first-wave of U-Boat captains.

The stamp of ruthlessness that comes with the submarine was applied early. U-156 and the other boats involved rescuing Laconia survivors were legitimate targets of Allied ASW forces and the Allies at no time promised a local truce. Particularly as how U-Boats would not hesitate to attack an escort or dedicated rescue ship stopping to save lives in a convoy battle.

Hyperbolic comments about war crimes add nothing to the discussion.

Edit: I suspect that if you look at the actual rules under which the Red Cross operated in WW2 you will find that no armed ships could legally fly the Red Cross under any circumstances. Also a look at the transcipts from Nuremburg fail to show any such declarations by Doenitz regarding the Geneva Convention and the Laconia affair. But I might have missed it.