The Taliban returned to power in Afghanistan in 2021, twenty years after their ouster by U.S. troops. Under their harsh rule, they have cracked down on women’s rights and neglected basic services.

President Donald J. Trump has wide latitude to enact the sweeping changes to U.S. foreign policy that he has promised, but his executive authority is constrained by congressional legislation, treaty …

U.S. and international sanctions have battered the Iranian economy and brought Tehran to negotiate over its nuclear program. Lifting them is central to a deal but will be a complex process.