The Official Nations At War Mod For BF2. 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.