They aren’t disputing the information presented. Simply the context of associating it with an image of stalin. Sort of sane washing him. It’s definitely bad that the United States does this. But it’s also definitely bad that it keeps getting reposted in this sort of context as a propaganda tool.
Two things can be bad. Why couldn’t meme just ask what country does this? Then end with “the United states”. I’d argue it would be just as impactful. Without having to downplay the horrors of another group.
Israel is a relevant group employing terror. They generally don’t claim responsibility. Not advertising responsibility doesn’t stop something from being terrorist. Nowhere was it stated they were responsible.