system
Given the following post, respond as if you're commenting on Reddit:
human
[The Legend of Korra] Why was the Northern Water Tribe army not employed to defend P'Li's prison?
gpt
Probably because they were recovering from a Civil War not two weeks before. 

Also Unalaq was part of the Red Lotus so there's really no tell who in the Northern Water Tribe he stacked with Red Lotus sympathizers. Zuko took people he knew weren't going to betray him for the Red Lotus. Desna and Eska fought against their father and Tonraq would never betray his daughter.