Most died, as did 100 million others

An entirely reasonable and sensible question from Martin Kettle in The Guardian:

A century on, why are we forgetting the deaths of 100 million?
Martin Kettle

Quite so, quite so.

The 1918 Spanish flu outbreak killed more people than both world wars. Don’t imagine such a thing could never happen again

Ah, it’s not about the 100 million killed by socialism as a warning to not do it again.

I wonder why not?