At what level of consciousness does he remain? What's the matter with him on this subject today?

He had some brain damage. He had to be retrained, but I don't know the extent of it. I know he has partial use of one of his arms.

How could I intervene in a situation like this where desire is so ingrained in the person?

I do not know. I'm not an expert outside of the fact that when you see someone in trouble, you decide to intervene or you do not. I didn't speak to him much after I left the military when he went into special forces. I sent him an email a couple of years later and his former wife responded and told me what happened.

Is he aware that he hasn't made it through "to the other side"? And what do you think about overcoming all physical expectations and continuing to exist, even against your will? Would he return to health completely, would he change his outlook on life or would he just be sad for not having been able to end his journey?

At the risk of making myself sound callous, I'll say this: No one knows what tomorrow will bring. My wife and I have life insurance set aside for my family. My wife and I have living wills. She wants the plug pulled if something leaves her in a vegetative state. I want the same. We both want to be cremated. She wants her ashes spread along trees in a park. I want something less formal.

I don't know what your friend or his family feel, but I wish all of you the least pain possible.