No matter what someone else has done, it still matters how we treat people. It matters to our humanity that we treat offenders according to standards that we recognize as just. Justice is not revenge - it's deciding for a solution that is oriented towards peace, peace being the harder but more human way of reacting to injury. That is the very basis of the idea of rights.
Revenge tries to solve the problem of vulnerability. If I strike back, I transfer vulnerability from myself to the other. And yet by striking back I produce a world in which my vulnerability to injury is increased by the likelihood of another strike. So it seems as if I'm getting rid of my vulnerability and instead locating it with the other, but actually I'm heightening the vulnerability of everyone and I'm heightening the possibility of violence that happens between us.
If you are asking whether states and state actors can only respond through revenge, then you are suggesting that diplomatic solutions are hopeless.
There was a brief moment after 9/11 when Colin Powell said we "should not rush to satisfy the desire for revenge." It was a great moment, an extraordinary moment, because what he was actually asking people to do was to stay with a sense of grief, mournfulness, and vulnerability.
I think maybe the destructive pleasure got turned into the destructive pleasure of war (something we see still in the images of US soldiers urinating on the dead bodies of Taliban soldiers). Something of the pleasure in destruction gets unleashed, and then becomes part of war effort rationalised first as revenge (or justice defined as revenge). But then it takes new forms, as we see now.
