the only way a conversation is possible is when both parties are making an honest effort to understand the other and arrive at the truth of the matter.
do you really think that if your cousins were killed 4 blocks away you wouldn't be particularly affected? Quite right, you would be less affected than if it were your siblings in your street. And more affected than if it were acquaintances in the next town. That IS the way we work.
Why say there's no categorical dividing line, it's good enough to accept as valid. We can all make the same list - what, you think some people are more affected if it is strangers being bombed in the next country than they are if it's their loved one in the living room?