The tunnels to/from Sinai have broken the Israeli blockade. It is their link to the outside world, for everything imaginable -- toothpaste to perfume, engine parts to lightbulbs. Egypt no longer can enforce their side of the border, the Bedouins are only too happy to trade with the people of Gaza. Even if Israel manages to get ground troops to the tunnels to destroy them (air power is useless) they wont be able to keep trade closed over the medium term. The blockade is finished, so Israel better rethink their strategy of self preservation by way of humiliating and imprisoning Gazans.