I didn't heard anything of Europe, Usa and lethal drugs.
About deterrence of to be afraid to be killed by our actions, if one thinks in the lot of stupid risks of dying (by driving drunk, smoking, etc.), the society can't trust much in the deterrent reasoning.
I mean that the countries without technology for A-bombs could have however nuclear submarines. The destruction of one adds the risk of nuclear wastes to regional wars.
I readed in a book of history of jet aircraft that a missile was fired by accident. A drop formed by condensation caused a short out, but one doesn't know when it's true or not because it's secret.
The author of the book had an english surname, maybe he was american.
Here the official version is that the fourth bomb searched by the submarine finally was hooked in a fisherman's net. Someone who was mentioned in the newspapers of these years (no free press then in Spain).
It's not only a possible accident with A-bombs. There have been accidents with nuclear-powered submarines. It's a source of power not surpassed by now.
RE: Death Penalty? Yes or No?
In my view painless means not the same as humane. There are many reasons besides pain.As I've understood with the cocktail one loses conscience before the truly lethal injections. A little like before surgery.