How does a refugee get into the U.S.?
Refugees must undergo an 18- to 24-month screening process, minimum, that the United Nations' refugee arm oversees. And that's before individual countries even begin to consider a refugee's application and conduct their own additional interviews and background checks.
The screening process generally includes multiple interviews, background checks and an extensive cross-referencing process that tests refugee's stories against others and accounts from sources on the ground in their home country.
Throughout that process, U.N. officials and local government officials in temporary host countries like Turkey, Jordan and Lebanon look to determine the legitimacy of asylum seekers' claims and ensure that they meet the criteria of a refugee, including that they are not and have not been involved in any fighting or terrorist activities.
Refugees also have their retinas scanned and have their fingerprints lifted.
Christopher Boian, a spokesman for the United Nations High Commission for Refugees, called the process "stringent" and "long and complex."
"If at any stage in that process there is ever the slightest shadow of a doubt or the slightest whisper of suspicion, they are removed from the process. That is that," Boian said.
"The very, very few Syrian refugees who are accepted and referred for consideration for resettlement in another country -- there simply is no more closely scrutinized population on earth these days," he added.
That's because other countries have so far pledged to resettle just 159,000 of the more than 4 million Syrian refugees -- setting an extremely high bar for resettlement.
And refugees aren't automatically considered for resettlement: only the most vulnerable refugees -- such as torture victims, female heads of household, people with serious medical conditions and other especially vulnerable groups.
So after they go through that process by the U.N., the U.S. does an additional screening?
That's right. After a rigorous screening process and several interviews carried out by the U.N. refugee agency, refugees the U.S. agrees to consider for resettlement have to undergo an additional interview, medical evaluation and security screening.
According to one U.S. government official, there's an additional layer of vetting that's specific to Syrian applicants, including special briefings for interviewers and information from the U.S. intelligence community.
The security screening involves checks against several government agencies' databases and terrorist watch lists using biographic and biometric information. It's a process Mark Toner, a State Department spokesman, recently called "the most stringent security process for anyone entering the United States."
And Syrian refugees get an additional, more targeted layer of screening involving the U.S. Intelligence agency, according to a government official.
READ: How do Syrian refugees get into the U.S.?
Sounds pretty rigorous. How does the refugee process stack up to other ways of getting into the U.S.?
The refugee program is simply the toughest way for any foreigner to enter the U.S. legally.
For most people, getting a tourist visa to enter the United States is much easier, but still requires an in-person interview and involves a typical background check. The process takes anywhere from a few days to a couple months.
But there's an even easier way to get into the U.S. if you're a citizen of one of 38 mostly European countries, including France and Belgium.
Travelers from those countries don't even need to first apply for a visa to get into the United States. They buy a ticket, grab their passport, and undergo the usual screening from U.S. customs officials when they land in the U.S. They are still checked against security databases before they get on the plane and upon arrival.
The fact that most of the Paris attack suspects were European citizens who would have had access to the visa waiver program is setting off some alarm bells. At least one of the eight Paris attackers likely
would have been able to travel to the U.S. under the visa waiver program, U.S. national security officials told CNN Friday....
Sen. Angus King, an independent from Maine who sits on the intelligence committee, said it "would be much harder" for a terrorist to get into the country through the refugee program than with a passport from one of the 38 countries in the visa waiver program.
"(The refugee process) would take 18 months to two years. Under the visa waiver program, it could take 24 hours," King told CNN in a phone interview. "The target of our work should be strengthening the visa waiver program."