It's likely he will continue to blame anyone and everyone he can until he must face the fact that only HE is responsible for how he deals with these perceived slights.
He will either get on the plane tomorrow or he won't. He will either stop drinking or he won't. He will either find something to live for, or he won't. I know you probably don't want to accept any of this, but what choice do you really have? I suppose you could go get him, and lock him in a room in your house until he decides he has had enough, but is that the kind of life you want for him? For yourself? Prisoner and jailer? How long do you think you could reasonably sustain such an arrangement?
Of course there are no guarantees, but I actually think it is a good sign that he is telling you these things. It might mean that he wants attention more than he actually wants to die.
The cops are not as close to this situation emotionally as you are. They likely see this dozens of times a week. He IS just drunk. It is not illegal to be drunk, and they are not trained therapists.
The only way to the next phase of this whole business is to accept that you are powerless over him and his choices--and so is everyone else who is not him. That includes the cops, the state, his ex-girlfriend, his grandparents, everyone.