History is written by the victors and before you say anything, my late Maternal Grandfather, son of German immigrants, was a Corporal in the Infantry, 42nd Infantry Division, AEF in the trenches in France. He came home with Krupp steel in his hip along with his own bone splinters. Grandpa believed in what he did and the rightness of it. I respect his memory, but I am also trying to be objective about history.
“then the British were committing war crimes by using a civilian transport to carry war munitions and worse, using civilians as human shields.”
War crimes didn’t exist back then, otherwise you would need to retroactively indict nearly every country that ever existed.
Here's the point: regardless of what the British "were" doing on the L, the U-boat captain had NO WAY of knowing that; certainly no record of heavy uses of passenger ships of this type, therefore it was still indefensible on his part. Regardless, the U.S. should have gone to war over the dozens of OTHER sinkings of neutral ships that the Germans engaged in.