Are you nuts? The Northern Water Tribe is the biggest group of morons in AtLA.
Person 1: Hey, look! The firebenders have stopped attacking! Now we can use our waterbenders to attack instead of defend. This will be a piece of cake, now that it's night and the moon is almost full.
NWT: What do you mean? How can we attack?
Person1: Haha! Listen to this guy. Always the kidder.
NWT: ...
Person 1: Um... hello? They are on boats.
NWT: ...
Person 1: Which are on water.
NWT: ...
Person 1: Which you can control.
NWT: ...
Person 1: BEND THE STUPID WATER, MAKE A TYPHOON, AND KILL THEM ALL! YOU HAVE ALL NIGHT!
NWT: Hmm... Nah. We'll wait until they reach our shores before attacking them.
Northern Water Tribe: Dumbest civilization ever.