[verb ない → なけ] + ればそれまでだ
The grammar pattern ばそれまでだ / たらそれまでだ expresses the idea that if something happens (or is done), then that's the end of it – everything is over, all effort is wasted, or nothing more can be done. It conveys a sense of finality and resignation, often with the nuance that all preceding effort, value, or meaning would be rendered pointless.
The literal meaning of それまでだ is "that's as far as it goes" or "that's the end of it." Combined with a conditional (ば or たら), it creates a pattern meaning "if X happens, then it's all over / it's all for nothing."
Expressing that effort becomes meaningless: When warning that a certain action or event would nullify everything that has been built up or worked toward.
Expressing resignation or acceptance of an inevitable outcome: Used when acknowledging that if a worst-case scenario occurs, there is nothing more to be done.
Dismissing something as pointless if a condition is met: Sometimes used to express that something has no value or significance once a certain line is crossed.
Both conditional forms are used interchangeably in this pattern with the same meaning. ば tends to sound slightly more literary or formal, while たら is more conversational, but in practice both are common.
This expression carries a fatalistic or resigned tone. It is used as a cautionary statement – warning someone not to let a certain thing happen because the consequences would be irreversible. It can also be used philosophically to accept the limits of human effort or control.