If Israel nukes Tehran and Damascus, they might not lose a battle that they otherwise would lose, but do you honestly think Israel as a country could survive after that?

Any conflict in which Israel has to use nuclear weapons is one in which its only goal can be to save the Jews in Israel long enough for them to escape Israel.

It's mutually assured destruction, Middle East style. There would be utter devastation among Israel's enemies, but it would be impossible for almost anyone to justify "oh, Israel is a GREAT idea!" if it came to that.

So the observation about Israel's power doesn't actually make for the lack of an existential threat. The existential threat is that they will have an endless wound in their side (Hamas) and maybe their other side (Hezbollah) and if they try to staunch the wound--or if they don't and their enemies are emboldened and miscalculate!--they would have to act in ways that were inconsistent with Israel's survival.