Your scenario suggests that the friend ‘just started’ to act out, but this breaks the analogy because the US has been doing war crimes for decades.

This isn’t a friend that just started acting out, it’s a friend that has a history of talking behind your back, stealing your stuff, crashing your car, sleeping with your SO, killing your pet, and offering you a cash bribe in return.

Why is this person still your friend? Why didn’t people reach their limit when the friend killed a million innocent Iraqis?