The future of global security will depend in large part on the fate of today’s 1.2 billion young people. Do youth between the ages of 15 and 24—a critical phase of life—possess  the necessary social, physical, intellectual, and financial building blocks to underpin productive, healthy adulthoods? Or do they lack this solid base, putting them at risk of personal and social instability?

Featured side by side at the top of The New York Times home page recently were two stories: one on the United States and China, the world’s largest producers of carbon emissions, committing to a global climate agreement, another on how rising seas are already affecting coastal communities in the United States.