The Legend of Korra, Season 4

[Discussing Kuvira taking the spirit vines for a weapon]

Raiko:
She might use the weapon to attack Republic City. The only way to protect ourselves is with a preemptive strike.

Tenzin:
My airbenders won't be part of an unprovoked attack!

Izumi:
Neither will the Fire Nation.

Raiko:
But, Fire Lord Izumi, Kuvira is a threat to the world! She has to be stopped!

Izumi:
The Fire Nation has spent too much of its history fighting nonsense wars. And I refuse to drag my nation into another one unless there is no other choice. If you attack Kuvira, you'll do it without my army.

Raiko:
Fine. I'll hold off any plans of attack. We'll go on the defensive and fortify security on the borders.

Izumi:
In that, you'll have my help.