I've been hearing that some Maltonite Harman has been providing you some "advice" in the Tennpenny Hotel located in the Capital Wastelands. Don't trust the harmans, they've been rather incompetent in stopping the superior zombie hordes. But, I've been having a friendly rivarly with this particular Harman scum lately, actually...so...
There's a third option, you know. You can find a way to get both the ghouls and the humans happy and have peace. It will require you losing not gaining an important semi-useful item though, and there will be bloodshed...
EDIT: (Actually, looking at my sources, it may not even require bloodshed. But, in any event, the solution is fairly obsurce. Joker-boy, want me to say it?)