What drove Filitov to betray his country, and how does he justify his treason?

Filitov himself is uncertain why he betrays his country, but the premature death of his beautiful ballerina wife figures in his motives. One of Filitov's sons died on the battlefield through the incompetence of his leaders. And apparently many of his military comrades were victimized and abused by the state apparatus. When Filitov imagines his World War II compatriots, he sometimes views his treason as revenge for those who fought and died for a foul government.