The 2010s were a decade defined by migration. At the start of the decade about 220 million people lived outside of their country of birth. By the end of the decade that number had risen to 270 million, according to the United Nations.
While many of these migrants left for economic opportunity, the three largest migrations between countries were a result of crises. Due to the civil war in Syria, over 3.7 million people left Syria for Turkey during the 2010s, and over 1.1 million left for Lebanon—these were the top two shifts of people in the world from one country to another. There was also a 500,000-person increase in the number of people from Syria in both Jordan and Germany. (The data counts the net migration between countries, so if people migrated and then returned to their country, they would not be counted.)
The Syrian civil war may have been the defining geopolitical event of the decade, shifting the internal politics and foreign policies of countries across the world. Through provoking a backlash against immigrants, it may have even contributed to the rise of populism in Europe and the United States.
The third largest migration was between Venezuela and Colombia. A cratering economy and unstable politics have led to over 4 million people leaving Venezuela since 2015. At least a million of them have left for Colombia, and while those migrants have been mostly welcome, helping these migrants is beginning to strain Colombia’s resources.
The fourth and fifth largest migrations were from China and India to the US. These were often highly educated migrants seeking economic opportunity. These are also among the most populous countries in the world, so large migrations between them is to be expected.