if… then It is all in vain, it’s done, it is useless, no point, it is a waste, that’s it, it is all gone,
Verb [たら] + それまでだ
Verb [ば] + それまでだ
(A) [conditional]それまでだ is a phrase meaning that if A happens, then all ends - implying that efforts and resources are wasted. It is often used when advising someone to avoid A. The phrase is frequently following ても (even if).