The main military thing going on there - I was in Dahab where there are endless military checkpoints - is Hamas like guys trying to come over and overthrow the fairly moderate Egyptian government and replace it with a hardline Hamas type islamic dictatorship for the glorification of Allah etc. Again it's not about reducing scarcity - more about increasing scarcity in return for political control. Dahab and Cairo are both a few hours drive from Gaza.
The rest is fees from the Panama (EDIT: Suez) Canal and tourism. Getting into a war, particularly with a country on the Red Sea, is suicide. (Also, the main flash point between Egypt and Ethipia has receded since the GERD finished filling.)