Putin and Trump have the capacity and responsibility to cooperate to make sure we are not humanity’s last generation. There are existential threats to all lives within their unique purview which they must address. Whatever else they may do, they must not ignore their duty to reduce these dangers.

Over 14,000 nuclear weapons still hang as swords of death over the world, and risk being used by accident, design or madness. In Helsinki, Trump and Putin alluded to the need to address nuclear threats, but didn’t commit to any concrete steps.

Virtually nothing substantive was said in Helsinki about the despoliation of the global commons. Yet the living systems upon which we all depend—the climate, the oceans, the rainforests—are under threat. 50-70% of our oxygen comes from phytoplankton, which requires healthy oceans. Protecting them requires global cooperation.