ない事(こと)には～ないUnless you do something

ないことには～ない is a 2-part structure in Japanese that is used to express that 'unless you do (A), (B) will not happen or exist'. This is a combination of ない, こと, に, は, and then something followed by ない in the (B) part of the sentence. Literally, it just means 'within the situation of (A) not being a thing, neither will (B)'.

This structure may appear with verbs and い-Adjectives in their ない forms, or nouns followed by でない.

In sentences that use ないことには～ない, (A) can be considered the condition for (B) being able to occur or proceed.

Caution

Occasionally, ないことには will be seen in sentences that do not finish with a word in the negative form. In these cases, ないことには implies that not being in the state of (A) will negatively affect (B). This translates similarly to 'without (A), unfortunately (B)', and often has structures like しまう following (B).