there's only one thing for it

there's only one thing for it

There is only a single course of action that can achieve the desired or necessary result; there is no alternative to a certain course of action. The virus wreaked so much damage that I'm afraid there's only one thing for it: we'll have to replace the entire computer infrastructure.
See also: one, thing
Farlex Dictionary of Idioms.

there’s only ˌone thing ˈfor it

there is only one possible course of action: Well, there’s only one thing for it, I’m afraid. You’re going to have to tell him what you’ve done and hope he forgives you.
See also: one, thing
Farlex Partner Idioms Dictionary
See also:
  • nothing for it
  • there's nothing (else) for it (but to do something)
  • there's nothing for it
  • damned if I do, damned if I don't
  • damned if you do, damned if you don't
  • I'm damned if I do and damned if I don't
  • when in doubt, do nothing
  • while you are at it
  • take action
  • action stations