Many described the risk of a Hezbollah -Israel war as mutually assured destruction. That has a deterring effect - as long as you have rational actors. Once one side (Israel in this case) is willing to endure mass destruction, the deterrence is gone.

of possible interest

The outrageous thing here is that the rest of the world is not willing to help Lebanon AND Israel find, catch and execute Hezbollah members for a very clear crime of not being anti-Assad.

what's the degree of destruction that Israel risks here?