Jack Bristow, a longtime agent of the CIA and former double officer with SD-6, is often emotionally distant and can be among the show's coldest and most brutal characters. However, his character's defining trait is his devotion to the safety of his daughter, Sydney. He is highly protective of her and is willing to do anything - torture, kill, even betray his country - to ensure her well-being. His relationship with his daughter has always been problematic, although it warmed and matured as the show unfolded.