expression
have to; have no choice but to; cannot help doing
A formal, somewhat literary expression equivalent to ざるを得ない. Attaches to the -nai stem of a verb to express unavoidable obligation or compulsion. Often used in written or formal speech.
See also: ざるを得ない
彼の提案には反対せざるを得ぬ。
I have no choice but to oppose his proposal.
この事実を認めざるを得ぬ。
I cannot help but acknowledge this fact.