This movie relates more than just a story of "Vengeance". Besides proving that killing begets killing - it consists of numerous fine details that reveal the hard work done at getting to the depth of things:
For instance, only characters that get shot in the head slump to the ground. The rest take time to die - they walk a few steps, spurt blood and express a look of helplessness and inevitability before going out. Yes its horrifying to look at, which is the point, but it is also real.
Every character is different, and though common in their desire for vengeance, their temperaments are clearly distinguishable in the way the hit men approach their task. Even the terrorists are not stereotyped into hysterical, screaming lunatics. They range from the visibly nervous to the cool Abu Salameh with the movie star style. They are poets, intellectuals and guerrillas each with his story of the conflict. They speak passionately about home - a recurring theme, along with "family". Moreover, Spielberg does not attempt to mitigate the grotesque manner of their deaths, for the blood of the targeted men flows as freely as that of their victims - and when they are blown up, their body parts dangle from ceiling fans. You are not here to feel satisfaction over anyone's death, Spielberg says to the audience. Or as Caine would say in Kung Fu: "The taking of a life does no one honour."
There are no easy "shoot-em-dead" eliminations. There are neighbors, bystanders and obstacles that must be avoided and protected - with variable success. Innocent people may be harmed - and one has to live with that.
There are no mathematical certainties about the potential damage a bomb will cause.
Perspectives and convictions can change, sometimes regrettably. "Don't think about it - just do it" says Avner at one stage when a member of the team expresses doubts about a target's guilt. But at the end he wants evidence that the men he despatched were justifiably killed. Implausible? No; it is only when he has been reunited with his family and experiences the affection of wife and child that he allows himself to reflect from a different perspective - their targets had families too - what if he had killed the wrong men?
The paranoia that permeates the world of spies and assassins is built up gradually - to the point where every survivor mistrusts everybody else. One is doomed all one's life to walk with ears strained for following footsteps. The length of the movie creates the right atmosphere for this idea.
The end dissatisfies many because they would like a reassurance, a note of optimistic finality - but Spielberg rightly offers none. It would be dishonest of him to offer a false but comforting illusion.
It is interesting to contrast this movie with "Paradise Now" that has no violence, a modest budget, and views the conflict from the Palestinian camp. Both narrate completely different stories - yet, in their respective ways, both humanize their subjects, defuse myths about glory, and arrive at the same conclusion: "There's no peace at the end of this."