Children undergoing cancer treatment were among patients evacuated from a hospital in Iran after US missiles struck nearby, according to Iranian state media. The incident came as Washington launched a second wave of strikes within 24 hours, further escalating tensions with Tehran.
https://www.hoover.org/research/stalins-genocides
https://en.wikipedia.org/wiki/List_of_massacres_in_the_Soviet_Union
That’s nowhere near complete.
Also, it didn’t stop once the SU ended.
All in all I really don’t think we need a race for higher numbers here, once a certain number has been reached. And it has been reached by both USA and USSR/Russia.