User blog comment:Damac1214/Back in Black - Call of Duty: Black Ops III teased, reveal trailer coming April 26th/@comment-6343006-20150409174651/@comment-25261281-20150409184648

World at War II implies it will be set during WW2.

BO is set during the Cold War. And it's not like the entire plot is connected to WaW's. It isn't a sequel like MW2 was a sequel to CoD4.