The former Jonas Brothers star is convinced his pop peer's life was hurtling towards an "explosion" because of his young age and the lack of stabilising figures in his life.
Jonas points the finger at Bieber's father Jeremy, who has been spotted enjoying several nights out with the star, who at 20, is still not old enough to drink alcohol legally in his adopted America.
Jonas tells Scene magazine, "I've had an easier route than most. The youngsters just turning 20, the Biebers of the world, are under a microscope. Bieber is having a very tough time finding balance. I think we all saw it coming. Your dad is your party animal - that's going to sum it up pretty quick. There's an equation for some sort of explosion."