When James D’Arcy was announced as a recurring character for season 7, THR described his character, Anson, as an arrogant former special ops agent who went to The Farm (the CIA’s Camp Peary) with Carrie.
In dialogue during “Active Measures,” it’s revealed that Anson and Carrie have a sexual history in addition to a professional one. During the ops meeting in Maggie’s kitchen, other missions they were on are discussed, including one where Carrie (maybe?) stole a car.
As for theories on Anson, he’s being set up to be a volatile, unstable guy who isn’t afraid of getting his hands dirty. That doesn’t sound like someone who would put the brakes on Carrie. Instead it sounds like Anson could be a very dangerous partner in crime for her moving forward. One without much of a moral code from what we’ve seen so far.