According to the United Nations, there is currently an unprecedented number of displaced people in the world; almost 34,000 people a day flee their homes to escape conflict and persecution, per the UN's 2015 statistics. Out of the estimated 21.3 million refugees in the world, only a small portion resettle in the United States. Since the federal refugee program was created in 1980, 3 million refugees have entered the U.S., with 85,000 entering between October 2015 and September 2016.

The Refugee Act of 1980 established a resettlement program and federal standards for screening and admitting refugees. Just how does that vetting work?

For most refugees trying to enter the United States, the process takes between 18 and 24 months and involves referrals from the United Nations, security checks and interviews with several national security agencies in the U.S., fingerprinting, and a health screening. According to the State Department, “No traveler to the United States is subject to more rigorous security screening than the refugees the U.S. Government considers for admission.”

First, applicants have to register as refugees with the U.N. High Commissioner for Refugees (UNHCR), which works in 128 countries and runs refugee camps in places like Turkey, Jordan, Thailand and Tanzania. Being a refugee means you’ve fled your home country and are afraid to return based on fear of persecution related to your race, religion, nationality, social group (like if you’re LGBT), or political views. Ideally, you have documents that confirm your story, like letters or written testimony from friends or relatives who know your situation. Sometimes an NGO or the U.S. consulate can refer you to the UNHCR, but that’s rare.

UNHCR vets refugees for eligibility with an eye toward how vulnerable their situation is—like if they’re an orphan, a victim of torture, or if they have serious medical needs [PDF]. They also are looking to weed out people who aren’t eligible as refugees, such as war criminals. Only around 1 percent of the refugee population around the world is deemed a “strong candidate” for resettlement in another country like the U.S. or Canada. While you can put down a preference, refugees ultimately don't get to decide where they are resettled, though having family ties or speaking a particular country’s language can help.

Once the UNHCR determines that a refugee is eligible and collects their documentation and biographical info, they get forwarded on to one of nine Resettlement Support Centers that the State Department contracts with for such services. The center interviews them and puts them into a database of worldwide refugees, checks their information, and then sends it on to the other agencies that will conduct background checks. The National Counterterrorism Center, FBI, and the Departments of Defense, Homeland Security, and State all do background checks and screen refugees for threats of terrorism and any previous criminal history. The U.S. intelligence community also reviews applicants.

Then, all that information goes to the Department of Homeland Security and the Department of State. Those agencies conduct more interviews (in the refugee's host country) and check for inconsistencies in the refugee's story. After the Department of Homeland Security decides you are not a national security threat, you get fingerprinted. Your fingerprints are run through FBI, Department of Homeland Security, and Department of Defense databases to further screen for threats.

As a Syrian refugee currently living in the United States recently wrote in Politico:

"Over 15 months I was interviewed five times—in person, over the phone, by the United Nations and by the United States. They asked me about my family, my politics, my hobbies, my childhood, my opinions of the U.S., and even my love life. No less than four U.S. government agencies had the opportunity to screen me. By the time I received my offer to live in the United States, the U.S. officials in charge of my case file knew me better than my family and friends do."

After that, if the U.S. government believes a refugee is eligible for resettlement in America, they still have to undergo a medical check to make sure they won’t be a threat to public health once they arrive, plus take a class to learn about American culture and customs.

Once a refugee is finally cleared, they are assigned to a resettlement destination chosen by the resettlement organizations and the State Department. Officials from the nine resettlement agencies meet once a week to go over the applications and place refugees around the U.S.

Even once they go through all that, there’s still one last step in the vetting: Like any other international traveler, refugees have to go through customs and get screened by TSA.

Sound complicated? It is. To help you better wrap your mind around the steps, the Obama administration visualized this process in an infographic on the White House website:

Once a refugee makes it through customs, representatives from domestic resettlement agencies meet them at the airport to help them settle into their new communities. But the process still isn't entirely over. Finally, if they make it through all that, they still have to apply for a green card a year after resettlement.

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