This page describes the permissions that Warzone's Android app requests and why.
 Wake Lock
While you are watching a turn play out (watching attacks and deployments happening), Warzone prevents your device from turning the screen off. To do this, the app needs to request the Wake Lock permission.
This is necessary since it's common for players to not be touching the screen while watching a turn play out, causing the device to think you're not using it.
 Internet and Access Network State
The Warzone app needs to contact the internet since it's a multi-player game. Single-player games take place mostly on your device, so it doesn't need to record every move on the server when playing single-player. However, the app will still talk to the Warzone server in single-player, but only to download maps, thumbnails, and a few other minor things.