You mean they don’t know about the left being pro peace? Or that they are overcompensating because they do know?
There is a documentary by Adam Curtis about how the rhetoric in geopolitics changed to good vs evil, not just Reagan but all the third way leftists. A very successful PR / brainwashing campaign.
But ever since Ukraine started this has massively changed on reddit which is supposedly “leftist”. Presumably the “science and technology of propaganda” is improving. If the Irak and Afghanistan happened today, there wouldn’t be any major opposition to it online. There wasn’t any in mainstream media either at the time, but back then the internet actually was less… warmongery?