I have also seen this in action, and it was done on me. There may be tactical things to subdue someone, but when it happens in a relationship, I don't care how drunk a person might be, it is an indication that they can and will kill you.
In a relationship, it is about dominance. It's about who is physically stronger and who is the weaker one (physically).
I had black and blues on my neck for close to 2 weeks. I had to stay at a shelter.
When a man put his hands around a womans neck like that and can look her in the eyes, while he is doing that, that is one of the biggest indicators that he could and would kill her.
amy