Interesting... we vaccinate ourselves and allies and destroy the enemies with the pox?
I hadn't thought about it quite that way, but it is a possibility, I suppose.
I was mostly thinking that, maybe, Iraq or some future ME enemy, losing popularity in the ME, might launch a smallpox attack on one of their own neighbors to gain united Islamic/Arabic support against the west. Our preparations against an attack against ourselves would likely be viewed by the Islamics and Arabs as preparation for a clandestine attack against them.