I think we are not disagreeing much actually. I do agree that Israel will forcibly expel Arab civilians, as much as they can. I'll leave the actual border to the author, an Israel that borders Turkey seems a bit much, but in the TL's circumstances it is at least conceivable (the humanitarian catastrophe ensuing would be... well... really big).Mate, I hate to trample on your optimism, but Israel annexed Jordan last time around and wasn't shy about kicking the Arabs out. And that was the first round, before the attempted Third Holocaust. And remember, the title of this TL is the Footprint of Mussolini for a reason - Israel, for better or worse, is that very Footprint. With Mussolini urging them on, nearly nobody feeling sorry for the Arabs, and a populace hopped up on righteous vengeance and fury... Well, I think Israel's gonna get quite a bit bigger than that. And the locals will hardly be in any position to resist the nice men with the guns and an international coalition likely occupying their countries. And my guess for those Arab citizens, well...
Forced removal of them from Israel's new borders is, within this timeline, probably the best fate they could get in their circumstances. Better than the Lehi.
A rational Israel might not want to have a subject/quasi-colonial population, yes. But this isn't a rational Israel. This is an Israel that's just had a major city hit with a weapon that breaks established international law, facing a regime that has made clear in word and deed they're aiming to wipe out Israel entirely. This is an Israel that has seen two Holocausts and isn't going to allow a third. They are, rather understandably, furious, and have a league of fascist states egging them on. They want to punish the Arabs, and the tone of the in-universe accounts makes it clear they'll succeed beyond their wildest dreams. No, this Israel doesn't just not want a quasi-colonial populace. This Israel wants all Arabs out, period. And after the Tel Aviv attack, and the discovery that the UAR has been collaborating with Nazi fugitives, simple mass deportions is probably the least cruel answer they'll come up with to an "Arab problem".
Apologies, ranted a bit there.