User blog comment:Argorrath/Treyarch releases a BO2 teaser video called "Origins" for DLC 4/@comment-90.212.225.109-20130807225553/@comment-3091118-20130808031714

First, an ourbreak can only happen near a large source of 115, as the zombies thenselves can't turn people. Thus a global epidemic couldn't occur until more 115 was exposed to bodies, also the nukes spread massive amounts of 115 that were scattered across the planet.

Second, Five happens when the Origional characters tried to contact the pentagon. CoTD happens when the Origional Characters teleport to the 935 syberian ourpost.

Third, We have no proof of when the earth was nuked. As Hadford, Washington was abandoned in the fouties. While Die rise takes place some point after after 1996. So we have no definative date.

Fourth, we don't even know everthing that the Germans did in WWII or the Soviets did in the 60s when technology was more redally avalible. So it's not impossible for that to happen.

Finally it's a game, some amount of suspention of disbelief is need.