Trump's administration plans to ramp up prosecution of unauthorized border crossings. Here's the story of how it became illegal in the first place.
The Irish prime minister is in Washington for the annual shamrock photo op. But, with Trump in the White House, even usually placid U.S.-Irish relations are a bit dodgy.
Opening borders is the easiest way to tackle global poverty and it would make already wealthy countries richer, too.
In an unequal, globalised world, should we be able to move between states as freely as we can within them?
In the 20th century, governments considered the “total abolition” of passports as an important goal and discussed the issue in several international conferences.