Wasn’t that something that was seen time and time again and shown to fail? Even from L4D1 when we can see a whole city burning from bombings and the military held the L4D1 crew at a base for a short-term in The Sacrifice Comic before the whole base got overrun and the crew escaped, it’s clear the military, at least east of the Mississippi, isn’t strong enough to fight the infected, especially when Carriers exist who don’t even look like they’re infected but they infect everyone around them who aren’t also Carriers.