Read on for everything you need to know about the cast of The Undeclared War. Full list of characters in season 2The main cast for The Undeclared War is as follows. Hannah Khalique-Brown plays Saara ParvinHannah Khalique-Brown as GCHQ Malware intern Saara Parvin in The Undeclared War. The Undeclared War season 2 premieres on Channel 4 on Tuesday 21 July 2026. Add The Undeclared War to your watchlist on the Radio Times: What to Watch app – download now for daily TV recommendations, features and more.