GRAMMAR DETAIL

ざるを得ない

have no choice but to

Indicates that external circumstances make an action unavoidable, even though it is not desired.

Examples

予算が不足しており、計画を延期せざるを得ない。

The budget is insufficient, so we have no choice but to postpone the plan.

雨が強くなり、試合を中止せざるを得なかった。

The rain grew heavier, so we had no choice but to cancel the game.

急な病気で旅行を取りやめざるを得なかった。

Because of a sudden illness, I had no choice but to cancel the trip.

Structure: Attach ざるを得ない（ざるをえない） to a verb's negative stem to express an action made unavoidable by external circumstances.
Basic usage: 予算が不足しており、計画を延期せざるを得ない。 says that a budget shortage makes postponing the plan unavoidable.

Suru connects as sezaru
- する becomes せざるを得ない, and 延期する likewise becomes 延期せざるを得ない. Regular verbs attach the expression to the part left after removing ない from the nai-form, as in 行かざるを得ない or 諦めざるを得ない.
An unavoidable choice versus a decision
- 休まざるを得ない says circumstances leave no choice but to rest, while 休むことにした reports a decision to rest. The latter does not itself specify whether the reason for that decision was unavoidable.