Let's go further than some arbitrary low level point at looking at 'morality" and what happens with wars. Let's go ALL the way. And then maybe learn from it instead of always doing the same things that lead to wars in general.
Amnesia between wars is most heinous. War is PROFITABLE, that's why most of them happen. "Ideology" is always the scam ruse the high level profiteers use to pull off their scams for their profits.
I suppose you can point us all to a link to copies of those documents? As I understand it, those rail lines were not bombed as a strictly military matter. They weren't aiding the Nazi war effort, so they were very low priority targets. Now I would have bombed them anyway, but it's quite a different matter to imply that the "politicians" and even the generals really wanted more Jews and others to be killed in the camps. Most, but not all, didn't even know that the camps were anything more than concentration or relocation centers, and were quite happy to have Hitler waste resources on moving people there, and guarding them, that could have been on line against the allies. Some did know or at least suspect what was really going on. Others had been told by espapees and such, but thought it Zionist Propaganda, on a par with tales of German soldiers bayoneting babies in the Great War, which were untrue. Some may have even thought the "detainees" safer in the camps than in German cities and those under their control, which the allies were bombing day and night.