For starters, I'll hazard a guess that there will be considerably more living quarters within the compound than at most U.S. embassies. I would expect that there will be a larger than typical military detachment (I think the Marines usually provide security/defense at embassies, right?), and it may also be that in Lebanon the U.S. will import more U.S. personnel to perform administrative tasks that in most countries are performed by locals employed by the consular branch. If that;'s the case, I would expect all the imported staff to be house within the compound.