The European Union is bitterly divided and likely to remain so. Geopolitical tensions and terror threats aren't expected to abate. And the migrant surge will continue to cause political and social challenges.
1. Migrant crisis
Europe is facing the worst refugee crisis since World War II. The U.N. estimates 1 million people crossed the Mediterranean to escape war, poverty and persecution in their home countries in 2015.
With the security situation in the Middle East worsening, the influx is not likely to ease in 2016 and Europe is bitterly divided over the situation, with some countries refusing to take in their share of asylum seekers.
2. Terror threat
The new year started with a series of terror threats in Europe. New Year's festivities were canceled in Brussels, Europe's political capital, after authorities uncovered plans for suicide attacks. In Paris, fireworks were canceled following multiple terrorist attacks in November that left 130 dead. And in Germany, several train stations were shut because of terror alert.
Fears of terrorism and stepped-up security are likely to remain commonplace in Europe in 2016, as most countries increase their defense spending.
3. Tensions with Russia
Russia is becoming increasingly isolated in the world, and its relationships with Europe are the worst since the end of the Cold War. Russia has lost its last ally in Europe, after Turkey shot down its warplane near the border with Syria. Russian economy is struggling and the situation in Ukraine has stalled, but is not yet settled.