How many here knew that George Washington ordered slaughter of Indians during Revolutionary War?

[Sympthsical]

11. I think you're just about there with your understanding

There was a sentiment among many Americans who had lived and fought in the French and Indian War that Native alliances could be mercurial. There were even tribes who allied with different sides in the war but still considered themselves friends with each other.

There was suspicion of what we might term "race loyalty", that they could ally with others to turn against the colonists on a dime. I really do recommend reading the Remonstrance from 1764:

https://sourcebooks.fordham.edu/mod/1764indians-penn.asp

It's a very short document, and you can see how colonists were interacting with a lot of different tribes of varying alliances and loyalties, and a sentiment of, "Just group them all together and be rid of them," was spreading a decade before the Revolution started. Note this:

"Had these Indians disapproved of the perfidy of their tribe, and been willing to cultivate and preserve friendship with us, why did they not give notice of the war before it happened, as it is known to be the result of long deliberations, and a pre-concerted combination among them?"

There's this idea that had taken hold. "Sure, this tribe says they are friends with us now, but the Natives are all secretly in it together!"

It does make no sense on the macro level of reading history, because you're left with the obvious question you've asked, "Why would Washington do that to allies?" But when you get down to the granular level, what was happening in the west, how people along the frontiers interacted with and experienced many different Native tribes, their psychology isn't too, too different from some of the shittery we witness today.

Replace Natives with how people today refer to "the Jews" and it might give insight into what kind of thinking was going around at the time.