The world now the faces the very real possibility of a nuclear war between the U.S. and North Korea that the entire world would lose. In addition to massive loss of human life resulting from even a limited exchange of such weapons, the already overstressed populations of other species we all depend upon for survival would crash if forced to also deal with the environmental effects, accelerating our headlong rush toward extinction.
Complicating any attempts to avoid such a scenario is the delusion that surviving it is still possible, along with an apparent unwillingness by both adversaries to accept responsibility for the costs. This is a special case of the threat we already face as a species, where large groups of consumers are unwilling to accept the impossibility of perpetual growth or the responsibility for its pursuit crippling our planet's ecosystems to the point where further damage will reduce our ability to survive.
The most rational way to deal with both threats is for everyone to recognize their costs, agree that they are unacceptable, and commit to doing whatever it takes to eliminate them. We would have to admit that no one is better than anyone else in the sense even the last person to live would not be "winner," but rather the most pathetic loser in the history of the world. As a minimum, the two people facing off today must admit this fact and believe it.