In a world where people are more mobile than ever, nations are struggling to recalibrate who can be a citizen.

Here’s what to know about Trump’s proposal to add new restrictions in the U.S.—and how that compares to other countries.

President Donald Trump has falsely claimed the U.S. is alone in offering citizenship as a birthright. More than 30 countries ...

Around three dozen countries and the U.S. offer automatic citizenship to children born within their borders, regardless of ...