The Kenyans did that, plus, the U.S. has naval and air assets off of Somalia's coast to prevent a sea or air rescue.
This means that jihadis have to explain (to fund-raisers and potential new recruits) why they lost Afghanistan, can't start any trouble inside Israel-proper, lost Libya without a fight, and got creamed in Somalia (the birthplace of Al Qaeda - re: Blackhawk Down).
Those aren't exactly signs of Allah's blessings on them...