The Palsbarist argument: Israel started the conflict by invading Palestine and stealing Arab land.
The counter argument: The 1929 Hebron Massacre.
"The Hebron massacre refers to the killing of sixty-seven Jews on 24 August 1929 in Hebron, then part of Mandatory Palestine, by Arabs incited to violence by false rumors that Jews were massacring Arabs in Jerusalem and seizing control of Muslim holy places. This massacre, together with that of Safed, sent shock waves through Jewish communities in Palestine and around the world.
During the massacre, 67 Jews were killed and Jewish homes and synagogues were ransacked; nineteen local Arab families saved 435 Jews by hiding them in their houses at great risk to themselves."There are several ways to counter the Palsbara argument but I like the Hebron Massacre. When confronted with this talking point, simply present the historical fact of the Hebron Massacre and ask your opponent "why were Palestinians murdering Jews in 1929?" Israel did not exist, there was no occupation, no blockade, no land theft, none of the usual excuses for Palestinian murder. Heck, the Jews murdered in Hebron were non-Zionist Jews! Ask them this simple question and they will likely not know how to react.
If they don't present an answer, I would not explain the real reason (false rumors of Jewish violence on Arabs, etc.). Instead, I would just say "well, something must have caused those Arabs to want to kill Jews, and it isn't any of the usual excuses. Clearly the desire to kill Jews was there long before Israel even existed. Therefore, Israel is not to blame for the conflict, whatever that something is is to blame." I have never heard a satisfactory response to this statement, and I doubt you will either.