That's what I meant with regards to "speech" becoming very vague and stretching over long periods of time, making the individual expression rather insignificant and the concept very fuzzy and hard to tell apart from culture, tradition and history. Like a rain drop in a storm where all those drops combined are causing the flood, but to pin it on an individual rain drop and say "this one is responsible" is hard.

> Are all societies susceptible?

Given that we've seen some level of exterminatory warfare all over the place in history (I'm sure there's huge amounts that we don't know about because the victims have been annihilated), and it's not unheard of among other mammals as well, my money is on yes.

That some small nations did not wage war against their much larger and much stronger neighbors is not a counter example: the fact that chickens don't hunt wolves doesn't mean they're not predators, they'll happily eat worms, and will eat a mouse if they can catch it.