a wall is better than a war- until the wall no longer does its job.
If Hezbollah and Nasrallah are lunatic enough to start a war, then Israel has the right and responsibility to end it any way it sees fit. If that means making southern Lebanon a parking lot up to the Litani River, then that's what will have to happen.
If the people of Lebanon don't want to be living in rubble, with no food, no electricity, no sanitation, no medical facilities, etc., they should tell Nasrallah to cool it. If they can't or won't, then whatever becomes of them will be their own fault. Same goes for Gaza.