Yes, probably that would be the case.

I'm afraid this time Israel sees it as an existential threat to the statehood.

They already set two objectives: destroy Hamas fighting capabilities and stop Hamas from ruling Gaza.

Can't do that without invading and taking control of it.

Their main problem, as you probably imply, is that there's another Gaza, underground. They cannot take it without leveling it to its foundations.

Yes, probably big losses both sides...