"Friend or Foe" is t.A.T.u.'s second single from Dangerous and Moving, released in December 2005. For the single, t.A.T.u collaborated with some big names from the rock world. Dave Stewart has a hand in writing the single, Sting plays bass on the track and Bryan Adams has shot the striking cover sleeve. The song features ambiguous lyrics; it is unclear who exactly the words are directed at. "Friend or Foe" was the last single taken from "Dangerous and Moving" to be released in the United Kingdom.