At the end of the third season
Brody is hanged. It was approved by Dar Adal, Lockhart, and some other guy according to them on the presidential command.
But it seems unnecessary since Brody and Carrie were already in the safe house. It seems that the hard part of escape was done already. They even planned the future together like everything is fine. The rescue action was initiated already. What were the risks for the C.I.A or USA?
Put simply: Why they did it?