i think a good chant makes an implicit argument that shifts the conversation. Israel has made it clear for its entire history that it is incompatible with Palestinian dignity and freedom. This is not widely understood by Americans, who think peacetime is just and neutral, and that the conflict began either 1000 years ago over whose god is better, or last week when the New York Times said Hamas murdered thousands of innocents for no discernible reason.

"From the river to the sea, Palestine will be free" makes the argument that all the land between those bounds is occupied territory, and that the occupation will fall. Given a belief in the narrative of a holy racewar, it is easily misinterpreted as exterminationist. A quick conversation can solve this: "why are you calling for the extermination of Jews?" "I'm not. That's not what that means. Why do you equate freedom with extermination?" Then you continue marching, because you are not interested in fighting the racewar. That's the terrain of the zionists.