Avoiding WWII might do it.
There would still be a Zionist movement. But there were strands within the Zionist movement that actually had been in favor of a binational state for quite some time. And absent the Holocaust and the subsequent wave of emigration to Palestine, there would not have been such widespread support for Zionism from the West, nor the numbers to make it work.
It's possible the end result is just a small Jewish state, similar to the Peel Commission Plan. But you might also end up with a multiethnic Jewish state dominated by Leftists –*Mapam-types from the Zionists and secular (and in many cases Christian) Palestinians, aligned with the Soviet Union.
Now it's quite possible this state could devolve into a second Lebanon. But if you're lucky you may eventually have a state that has a multiethnic character – a large Jewish minority, Muslim and Christian Arabs, Druze, Armenians, and Bedouins.