I was offering a sketch of an explanation as to why one's moral obligation (?) might cease when one is surrounded by others who can potentially do equal harm to one.
At least in popular Buddhism, there is a defense of self-defense; but also in the Vinaya (monks are allowed to defend themselves). And as long as Buddhism permits self-defense, cessation of moral obligation toward others is on the table to be discussed.
My only reason for not being a Buddhist and "why Buddhism doesn't work for me" is that it appears to be nothing but a self-fulfilling prophecy.That's why your frequent strategy of "Buddhism doesn't really work for me, because of this theory that I can link to..." might be gratifying, but doesn't help.
Whatever social, philosophical etc. theories I mention is just to understand Buddhist philosophy through contradistinction with other philosophies. I am knowledgeable enough to take that route. I stand in the middle of the road ... and get hit by traffic from both sides ...
Conceiving of life as a life-or-death competition is kamma?You are describing a situation in which kamma has already arisen. If Dick or Harry has got themselves into a situation where they perceive people around them as threats, then that's their kamma right there.
(How many Buddhists do you know who tacitly operate with this concept of life? It seems to me that many do. I hadn't given much thought to Social Darwinism, for example, until I came in contact with Buddhists.)
Of course, if they do believe in kamma, then this changes what they consider to be "self-interest", and can differ from what is ordinarily considered "self-interest".If Dick or Harry are cognisant of the situation but adhere to a view in which they don't want to protect their interests first, they create different kamma.
In order to notice those views to begin with, what better way than to put views in contradistinctive relationships?That's why I'm personally wary of stuff like "Mutually Assured Destruction" and its application. And all other social "scientific" or personal convictions as to why "Buddhism can't work". Views.