Interestingly neither do the radical parts of the Democratic party. Iran just walks the walk as well. It is interesting to me to see an ideological alliance between a radical Muslim movement and a radical left wing movement, I think Israel's "disappearance" is the only thing they agree on.
De-escalation requires willingness. It's convenient for both Israel and Iran to escalate considering they both have hardline governments and growing opposition.
> no de-escalation mechanism? Maybe through the UN?
Possibly. Israel and Iran have friends in Moscow, so the usual Sinorussian veto party could be sidestepped. But this would require Russia extending its nuclear umbrella over Iran. That, in turn, gives Putin a say in Iran's extensive extra-territorial meddling. Tehran may figure they can get their own nukes out of Russia for a cheaper price.
Tellingly, America has only extended strategic ambiguity to Israel, the same as we give Taiwan, not a red-lined nuclear umbrella like we do to NATO or Japan. This doesn't seem like a problem great powers care to resolve.
No. Iran does not recognize Israel's right to exist, even if Israel goes back to pre-1967 borders.