Hi everyone, I'm roughly half way through the Dark Forest and just read the part where Rey Diaz' Wallbreaker finds him in his bunker. I know that Wallbreakers are part of the ETO but are they coordinating with the UN? Or are they purely antagonistic to the UN and the Wallfacers?

I can't remember if they explained the Wallbreakers before the first one showed up. At first I thought they were a check to make sure the Wallfacer's plan was sound.

The reason I ask is because at the Wallfacer meeting directly after that part the UN knows about the Wallbreaker and knows Rey Diaz' plan.

I didn't want to go searching for the answer in the sources because I don't want to inadvertently come across spoilers.

Thanks!