....create a 3k buffer into Gaza
The best way to deal with subterranian engineered structures is with low yield nuclear weapons:
It is one of the safest uses of nuclear engineering, basically a way to destroy underground structures with almost ZERO surface radiation (plus you create a nice, deep, nuclear-engineered ditch). The United States even wanted to use twenty nuclear weapons to build a trench through Nicaragua making a BIGGER Panama Canal. See: Operation Plowshares. But I digress.
Just look at the photos from Nevada. If they were all in a line, it would be a perfect, man made barrier:
The Isreaelis have all that they need:
1) CAUSE,
2) Nuclear weapons,
3) A 3km buffer to limit civilian casualties,
4) An urgent need to collapse the tunnels,
5) Finally, it sends a message to the rest of the Mud-slime world (especially Iran) that they are NOT afraid to use nuclear weapons (albiet, in a scientific, controlled, engineering sense):
Good thought. But it would probably harm the current fencing infrastructure.