If there is a wrong thing to do, it will be done, infallibly. One has come to believe in that as if it were a law of nature.

George Orwell (1903-1950) English journalist, essayist, writer [pseud. of Eric Arthur Blair]

Diary Entry (1941-05-18), “First War-Time Diary”
    (Source)

In context, Orwell is complaining about what he considers squandered opportunities by Britain to occupy Vichy French territories, such as Syria, before Germany could make use of them.

See Murphy's Law.