6000 000 bombs dropped by the US there now these guys trained Cambodians to fight Polpot then we pulled out abandoning them to their fate.
The scars of war motivated this pair of grumpy old men to return to help this country and themselves heal past wounds and sorrows from fate of those they feel they abandoned.

They are completing their mission, not on someone else's terms, but on their own. Now they are in control of what was an unbelievably horrific situation. Sometimes the only way to have closure is to go back and finish something.

In Doco it was touching to see the old boy killers shed tears as he lifted kid with no feet up on table at eye level to talk with them.These guys come home with not much thanks from their country and mental problems.Bomber used to get on piss and fight a lot and looks pretty fearsome but even the Cambodians that were scared of him to start with( because Tattoos are mainly worn by underworld) came to find him an understanding and loyal friend.Yes like you say the closure and healing are helped by returning but rusty old bomb defusing would give me nightmares.They have trained mothers as well as guys to do this dangerous work.