I’ve been thinking about this exact question recently.
My Austrian grandmother and her sister were working class teenagers during the war. They couldn’t realistically have done anything to stop the Nazis. They didn’t really do much to help but since they were seamstresses they secretly snuck the Jewish family in the building some sewing supplies. It wasn’t much and they stopped when they were told that someone had reported them to the Gestapo. Their experience during the war was dodging bombs and trying to find something to eat.
None of that matters. When I was a kid growing up in the US people regularly made Nazi jokes as soon as they found out about my heritage. Nobody was willing to entertain any ideas that maybe those civilians shouldn’t have been held accountable.
History judged all of Germany and Austria harshly. It judged the civilians harshly and it judged their descendants harshly.
https://news.un.org/en/story/2023/12/1144717
The world is watching.
The glaring difference between the two is our level of active involvement.
Solidarity is one thing. Actually doing something about Sudan would require some sort of deliberate intervention.
In the case of Gaza we could likely make a huge difference if we just stopped arming the aggressors.
We don’t send arms to Sudan. We don’t send arms to Putin. We don’t send arms to the Sri Lankan military. We don’t send arms to Boko Haram. We don’t send arms to Myanmar.