I've found the most involving use of revenge as a part of a story is when it is in fact very ruthless. Especially when it is ruthless and violent, but is motivated by a sense of justice. Often times, characters who are in such narratives begin with a black-and-white sense of morality and by the end of the story they have begun to notice the grey lines. Steven Spielberg's Munich dealt with this as a group of Israeli secret agents wanted revenge for an attack by Palestinian extremists and it felt honorable and proper to ensure the deaths of such enemies. The character of Avner Kaufman is completely changed by the experience for both better and worse. He has a greater understanding of himself and the world around him, but at such a great and personal cost to his own humanity.
The Debt explores a similar line of story and is also similar to Munich in that the characters are Mossad agents. There is the truthful perception that Mossad agents are very good at their job. In a sense, they are the super-spys of the grittier world inhabited by Jason Bourne as opposed to the gadget-based and supermanly accomplishments of an early James Bond. Based on the Isreali film of the same name, it tells a story that takes place in two different time periods.
In 1965, agents Rachel (Jessica Chastain, on quite a roll this past year), Stephan (Marton Csokas), and David (Sam Worthington) are tasked with finding a Nazi war criminal (the creepy Jesper Christensen) who is hiding in Russia under an alias. The film begins with and then has about a third of its story take place in 1997 where Rachel (Helen Mirren), Stephan (Tom Wilkinson), and David (Ciaran Hinds) are keeping secrets about what really happened on the mission from those around them who believe that the three soldiers are national heroes.
Director John Madden (Shakespeare in Love, Proof) manages an impressive ensemble and keeps the tension high with a lot of skilled editing and camera angles and also in-part to an already terse script by Jane Goldman & Matthew Vaughn (Kick-Ass, X-Men: First Class) and Peter Straughan (Tinker, Tailor, Soldier, Spy). That beign said, the film's core problem seems to be in its structure. As I pointed out, it only jumps back and forth maybe three or four times, but we are given enough about these characters to be able to draw connections to their past and present selves.
Rachel is vulnerable but well-trained, Stephan is to the point but likes to still have some fun, and David is troubled and professional. This stays the same across the line as far as transitions go with Chastain to Mirren, Csokas to Wilkinson, and Worthington to Hinds. The two stories are only linked through subject matter and character similarities, but really the purpose of the two separate chunks feel as if they are so different that it almost comes across like I'm watching two films instead of one. The first act of the movie is about trying to capture a man while the second half of the movie is about trying to cover up something about the capture of a man. The level of excitement goes down, while the level of interest in the fate of the characters goes up. For me, this is what puts the two storylines at odds for each other.
The saving face of it all is how the actors are all still doing some damn fine work. Each of the six performers reflect their character's responsibility he or she feels for their mission and that is what ultimately destroys all of them as the story progresses. They are only human and therefore they begin to notice the grey lines I mentioned above. They don't fall prey or interact too much with these quandries, but at least my interest level in the material is raised because of how the three of them decide that deception is a burden they should to carry to save face (a tangent does come to mind- wouldn't Hinds be a better physical choice for an aging Csokas than an aging Worthington, not that it ultimately matters).
The Debt is not as involving as one might hope, but it at least explores characters with a sense of humanity and how that is either strengthened or diluted because of their choices.