According to the UNHCR, over 3 million refugees, mostly from the Syrian conflict, are now in Turkey. That’s nearly 5 percent of the population. About 10 percent of them live in massive, ungoverned refugee camps — potential sources for extremist mobilization and transnational criminal activity, as Sarah Lischer has documented. In southeastern Turkey, where 38 percent of the refugee population is concentrated, opportunities for employment are scarce, and violence has increased significantly.

In Jordan, the government has sought to contain refugee inflows from Syria by concentrating tens of thousands of refugees in camps along the border, such as Ruqban and Hadalat. Armed militias have formed in these camps, which have been the target of Russian airstrikes.

Lebanon has the world’s highest number of refugees per capita, with an estimated 1.2 million refugees, mostly from Syria, in a country with a population of roughly 4.4 million. While Lebanon officially has a “no camps” policy, 90 percent of these refugees are located in just 251 localities, which are some of Lebanon’s poorest.