Say there's a region with just 5 nations. What happens when the event starts, will zombies just roll over the region because 5 nations working on a cure isn't enough, or is the effect proportional the number of nations in a region?
Also, what happens to people asleep when the event starts, it's not really fair if their nations get rolled over just because of their sleep cycle or location.
(No, I'm not going to drag this out into a huge argument like the last one, I'm just asking)