#I cannot get over how determine Bruce was in getting revenge for his baby and how scared everyone was of him

[littlefankingdom]

I think it's really important for Bruce's character, and to understand him more, to keep in mind how he did try to kill the Joker.

When Jason died, he was all about vengeance, he wanted that clown dead for what he did to his boy. And he had to be told by Clark to not do it now, as Joker was under diplomatic immunity, to not start a war. (I cannot get over how the US GOV was scared of Batman committing a murder. And Bruce even went in Joker's room to threaten him.) Bruce was going to kill that man and nobody could stop him. Clark didn't even try to. So, once Joker wasn't a diplomat anymore, he went for it. In the end, he left the Joker for dead, shot and going down with the helicopter.

Bruce did "kill" the Joker because he killed Jason. He went back to Gotham thinking he was dead. But the vengeance didn't do shit. It didn't help with the grief, it didn't help with crimes in Gotham, it didn't help the batfam, it didn't help Bruce. He spiraled in his grief and killing the Joker brought nothing, no closure. Tim came and helped him back up, and it's because of Tim, of love, family and hope, that Bruce, Dick and Alfred were able to heal from the grief and continue their fight.

When the Joker shows up again, more than a year after Jason's death and Batman letting him for dead, Bruce has started to heal and he can recognize that vengeance is useless. It's against what he stands for, and it doesn't help at all. This is a lesson he applies when he faces the man that killed his parents, he doesn't kill him because it would not bring them back, it would not ease the pain, it would be just violence to answer for violence, a continuation of the circle of violence.

And that's why he refuses to kill the Joker for Jason, when asked, or to let Jason kill the Joker, because it will not help Jason (Btw, Jason wasn't scared of the Joker until recently, so he didn't want Joker dead to feel safe in Under The Red Hood) It would just continue the circle of violence that they are fighting against.