I am not saying my way is a solution, but I see my way as the basic law of being human. I rather humanity perish because we can't sustain ourselves anymore than allow some people/group decide half of us needs to die in order for the other half survive and keep the human race going. We are a civilization, it may be 'efficient' and 'logical' but it is also barbaric. No matter which way you spin it, it is allowing, even hoping for, mass massacres and there is no justification for that, absolutely none.
Damn, I just remembered, have you watched Watchmen? It's a superhero movie, one of the more gritty ones. In the end, one (rational, entj I'd say) superhero decided to personally murder his superhero colleagues so that they wouldn't stop him as he planned to destroy all the major cities of the world to stop nuclear warfare before it destroys humanity. He saw that as the solution, to unite the world against a common supernatural power/enemy instead of each other and thus, bring everlasting world peace. I think you should watch the movie, it's idealized and simplified and clearly anti-xntj rationality, but it went over some basics of both arguments.