Back To The Wall Meaning

(idiomatic) (Can we clean up(+) this sense?) A very difficult situation with no beneficial options available for action.

Example: 1901, Frank Norris, The Octopus, ch. 8:
  From this place—so he told himself—had emanated that policy of extortion, oppression and injustice that little by little had shouldered the ranchers from their rights, till, their backs to the wall, exasperated and despairing they had turned and fought and died.
1910, Edith Wharton, "The Legend" in Tales of Men and Ghosts:
  Bernald felt that his extreme docility in such matters was proportioned to the force of resistance which, for nearly half a life-time, had kept him, with his back to the wall, fighting alone against the powers of darkness.
2006, Bobby Ghosh, "Why Iran Won't Back Down," Time, 14 Jan.:
  His back to the wall, Ahmedinajad resorted to the tactic favored by cornered politicians everywhere: distract attention from yourself by pointing to a bogeyman.