> Operating partly under the dictates of the old prize rules, the U-boat commander, Korvettenkapitän Werner Hartenstein, immediately commenced rescue operations. U-156 broadcast her position on open radio channels to all Allied powers nearby, and were joined by the crews of several other U-boats in the vicinity.
>[...] En route, the U-boat was spotted by a B-24 Liberator bomber of the US Army Air Forces. The aircrew, having reported the U-boat's location, intentions and the presence of survivors, were then ordered to attack the sub.
>[...] The commanders of the Kriegsmarine were quickly issued the Laconia Order by Grand Admiral Karl Dönitz, which specifically forbade any such attempt and ushered in unrestricted submarine warfare for the remainder of the war.
>[...] During the later Nuremberg trials, a prosecutor attempted to cite the Laconia Order as proof of war crimes by Dönitz and his submariners. The ploy backfired and caused much embarrassment to the United States after the incident's full report had emerged.
https://en.wikipedia.org/wiki/Laconia_incident
It's also specifically not about genocide vs non-genocide but about legal vs. illegal orders. Just because you represent the US of A you cannot lie to the whole world to start a war. I mean, you can as evidenced by Powell, but a lot of people will spit on your grave for that.
Really though, this is a stupid comparison. People generally remember the Nuremberg trials in the context of the Holocaust -- genocide, slave labor, and all the horror that accompanied it. Colin Powell did nothing remotely close to any of that, and while there is plenty of criticism to throw at the US for the invasion of Iraq there was no genocide, no ethnic cleansing, no slave labor camps, and a dozen US soldiers were thrown in prison by the US for having tortured and humiliated prisoners under their command.