The Culture War - Whose Culture are We Fighting For?

As Christians of all stripes are continually bombarded with the call to join the "Culture war" and "take back America," I always wonder which culture we are to fight for? As Christians, are we called to fight, defend and live for American Culture? Is American Culture the same as the Culture of Christ? If so, where does Scripture say this? And where does the Gospel of Jesus Christ fit into this scenario?