Gotta love your brand of moral relativism.
It wouldn't be the same if, for instance, they posed a direct physical threat to me or my close ones.
Many successful, influential people had drug and alcohol problems. Leaders, philosophers, writers, surgeons, entertainers, mothers, fathers, brothers and sisters have been addicts that were never a direct, physical threat to anyone but themselves.
That doesn't distract from the fact that this problem can be solved without resorting to vigilante justice and out right murder. Death shouldn't be the punishment for having a problem.
Here's an idea... those Filipinos over there have such a violent country! They just can't get there act together! I guess Filipinos are prone to violence, and they DO pose a direct, physical threat to everyone in the world! So, go ahead and kill a Filipino if you see one -- you'll just be putting them out of their misery -- and of course we're so benevolent, we offer free rehabilitation (AKA prison) for any Filipino that turns themselves in.
There are many issues which you can find common ground for a base case of moral absolutism when you are not being absurd.
Moral relativism allows you to accept the actual evil of other's actions as a product of their culture.
That is the kind of thinking that allows people to say genital mutilation is a cultural thing.
For me that's quite a line to cross.
Start fighting using non-violent means and maybe only resort to violence when confronted with violence from the other party.