The collapse of the Cold War–era nuclear arms treaty signals trouble for U.S.-Russia relations, European security, and nonproliferation efforts.

The European Union and the United Kingdom came to a last-minute trade deal on Christmas Eve, narrowly averting the hardest of all potential Brexits. But major uncertainty remains.

Political unrest is sweeping Chile, as impatience with inequality grows in what has been one of Latin America’s most prosperous and stable countries.

Anti-government protests could mean humanitarian crisis in Haiti, a country with a long history of instability.

The victory of pro-independence parties in Scotland’s elections means that another referendum is on the agenda. What’s at stake, and what comes next?