with all one's might

Prepositional phrase

using as much strength and effort as possible.

Japanese Meaning

全力で / できるだけの力と努力を尽くして / 力の限り

One must fight with all one's might to protect one's loved ones.

人は愛する人を守るために、できる限りの力を尽くして戦わなければならない。

Sense（1）

using as much strength and effort as possible.