Once a fringe movement, green parties are increasingly shaping the debate in countries around the world. How influential are they, and what comes next?

U.S. strategic and tactical nuclear weapons on land, in the air, and at sea, will undergo costly and extensive modernization in the coming years.

The European Union has navigated a thicket of external and internal crises in recent years, including mass migration and Brexit. What are the union’s core institutions, and what roles do they play?