Nations at War! A Single Player / Co-op & Multiplayer Battlefield Style Game, You won't need BF2 to play it. Here's the long awaited public release of Nation at war which is standalone mod for battlefield 2, It Works without battlefield 2 installed, You'll need your battlefield 2 cd key in order to play the game. Nations at War was built upon the roots of a small group of friends, some of which have played together for many years. Nations at War is a team based First Person Shooter (FPS) that seamlessly combines the use of air, ground, and naval vehicles. It is set in the present day and uses modern and developing combat technologies in its arsenal of game play. Nations at War redefines first person shooter game play by depicting warfare between different nations and regions. Game play involves players joining a country or alliance.