Blame plosive alliteration, if you will, but when people describe Homeland's Carrie Mathison, the words "brilliant" and "bipolar" are almost always used in the same sentence. She's mentally and emotionally unstable, the narrative goes, but she's also extraordinary: Although her brain chemistry thwarts her chances of lasting happiness, it gives her a broad streak of genius that makes her the country's most effective weapon in the fight against terror.
This argument, even as it's endlessly touted by the press and by Homeland's showrunners and by the actress who plays Carrie (Claire Danes), is unfortunately total garbage. Carrie is a terrible spy. If this weren’t a television show, she wouldn’t be allowed within 10 miles of Langley. Sirens would go off if her car so much as entered the GW Parkway. Yes, she has a history of mental illness that has seen her institutionalized and forcibly medicated; yes, she suffers from a related lack of impulse control, and is a narcissist with a complete lack of sympathy for anyone who isn't herself. But she’s also insanely unprofessional and sloppy in a way that’s more grating in Homeland’s fourth season than ever.
In her relatively short and extremely stormy tenure at the CIA, Carrie has slept with her boss (Estes) and broken up his marriage, seen one asset (Hasan) executed in Pakistan, lied to another (Lynne) that she was under CIA protective surveillance (after which Lynne was promptly assassinated), illegally spied on a returning Marine (Brody), slept with said Marine and given him information that helped him beat a polygraph, gotten another asset (al-Zahrani) killed by a briefcase bomb during a meet, gone rogue on the streets of Beirut, slept with Brody after she knew he was hatching terrorist plots against the U.S., gotten pregnant by Brody after she knew he helped assassinate the vice president, and then helped Brody escape after a bombing she failed to predict that ended up killing almost 200 people at Langley. And that's just the first two seasons.