._. I think I Cummed a little. This is super possible, because of the timeline. If you think of it, the Chernobyl Accident happened in 1986, and a few years later Price and Captain McMillan (Misssion All Ghilled Up) you go into Chernobyl to assassinate Zahkahav. So since this game is set is 60's - 80's, Zahkahav still had his arm, before they shot it off. And Zahkahav was a old man during present day COD4. What I am trying to say is that this whole Zahkahav being back thing is possibly true. Treyarch is a genious.
Im pretty sure that the order of the newer Call of Duty titles go like this (from past to present). CoW@W --> Cod:BO --> CoD4:MW --> CoMW2. Maybe someone can see what time periods the other Call of Duties go in and we can have a full chart.