So a bunch of Germans won a battle against some Russian reds and took a number of Russian and Jewish prisoners in the aftermath.
The Germans told the Russians to dig graves for the Jews or they would shoot every last one of them.
The Russians declined, preferring death. So the Germans asked the Jews to dig graves for the Russians. The Jews began working immediately (for the first time in their lives).
When they were done, the Germans said to the Russians, "Now do you understand why we do what we do?" and shot every Jew and buried them in the graves they dug up for the Russians.