Come to think of it, it doesn't really make sense for Iran to want this sort of escalation to happen. The ideal situation from its standpoint is for Palestine to be a continuous thorn in Israel's side, but not too much. That's cheap to do and disruptive to Israel. If Israel connects the killing of hundreds of civilians to Iran, that could be justification for all out war. That would be damaging for both sides, but ultimately I think Iran would come out the worse.

For a vaguely comparable situation, look to Ukraine. NATO is willing to arm and train Ukraine, but committing NATO soldiers involves incredibly high amounts of risk. That's why NATO has held back, even though its conventional armed forces would have no trouble taking on Russia.