expression
there's no other way; there are no other options
A fixed expression used when the speaker concludes that only one course of action remains. Often carries a tone of resignation or determination.
See also: 他に方法がない (ほかにほうほうがない)
この問題を解決するには、他に方法はない。
There's no other way to solve this problem.
彼を助けるためなら、他に方法はない。
If it's to help him, there's no other way.
Same meaning but uses が instead of は; は adds contrast or emphasis, while が is more neutral.
A fixed phrase composed of 他に (hoka ni, 'other') + 方法 (hōhō, 'method') + はない (wa nai, 'there is no'). The structure is a common pattern for expressing lack of alternatives.