conjunction
without; if it were not for
Conditional conjunction meaning 'without X' or 'if X did not exist'. Often used in formal or written contexts. The pattern is Noun + なくしては.
努力なくしては成功はあり得ない。
Without effort, success is impossible.
彼の助言なくしては、この問題は解決できなかっただろう。
Without his advice, we probably couldn't have solved this problem.