The new U.S. aid package will reestablish a critical flow of weapons to Ukraine’s military, but the war will hinge greatly on which side can ramp up and sustain its firepower and troop numbers in the…

U.S. administrations have backed sweeping efforts for societal change in the Middle East in recent decades, with poor results. But Washington can still achieve more modest, essential goals in the reg…

Governments and companies are embracing new emissions-reducing technologies that pull carbon dioxide out of the atmosphere. But it is uncertain whether this can work at the scale and in the time nece…