The Syrian refugee crisis has sparked a heated debate over what role America should take and whether or not we should accept refugee applicants. President Obama has pledged to resettle 10,000 Syrians, but he has met strong opposition among the states and a bipartisan majority in Congress.

According to a Bloomberg poll, just 28 percent of Americans support the plan to resettle the refugees under the normal screening process—without accounting for religious beliefs—and over half would not take any refugees at all. Most are concerned that after the recent terrorist attacks in Paris, it would be prudent to pause the resettlement in the interest of national security.

To counter the concern that inviting refugees might allow extremists to enter this country undetected, many refugee proponents point to the number of detailed screenings and background checks of our national security agencies as a safety net against such incursions. Yet, senior officials from the FBI and the Department of Homeland Security have warned that even with the vast array of resources at the disposal of these agencies, there is still a significant risk to our national security in taking in Syrian refugees. Accurately checking the background of refugees only works if there is information available on the person’s background.

The shattered government infrastructure in Syria, the lack of reliable government documentation, and the absence of criminal or terrorist databases has made vetting for potential threats nearly impossible.

Even Syrian passports are effectively worthless as identification because of the thriving black market. For about $250, migrants can buy a fake Syrian passport that can fool border guards. Without reliable Syrian databases with which to cross-check these documents, the fraud goes unnoticed. That is, until terrorists with fake passports pretending to be Syrian refugees snuck into Europe and attacked Paris.

Several Syrians have been arrested trying to illegally cross the border into America. Five Syrians with doctored Greek passports were arrested in Honduras, and eight more were arrested on the Texas border. Considering that about 1,000 illegal immigrants enter the country per day, it is entirely possible that some Syrians, perhaps even terrorist sympathizers, have already illegally entered the United States. Considering the Paris attacks and the problems of screening and documentation, the calls to pause the resettlement of 10,000 Syrian refugees is reasonably justifiable.

President Obama has criticized resettlement opponents for being “scared of widows and orphans coming into the United States of America,” but data shows that he should not dismiss their concerns so quickly. According to a Pew Research Center review of Eurostat data, 72 percent of asylum applicants are male and 54 percent are between the ages of 18 and 34. Welcoming thousands of military-aged men into a population with which they share few cultural values is not a responsible immigration policy and, as Europe is witnessing, does not promote stability or quality of life for either population.

Many supporters of refugee resettlement have humanitarian motives for acting, often assuming that America is the only wealthy country not paying some supposed debt to the rest of the world. They forget that Americans pay almost twice as much in foreign aid as the second leading country.

No one has a right to move to any country he or she wishes at any time. Europe’s experience has shown that the fantasy of a borderless world is unsustainable and dangerous, not only for Europeans, but for the countries from which they drain populations. While the struggle of the Syrians is lamentable, American immigration policy, which includes asylum, should put Americans’ safety first.

It would make more sense to shift our aid towards the countries neighboring Syria who could take in refugees. Those who struggle with the West’s values of secularism and individual liberty may feel more at home under Sharia law.

Many refugee proponents falsely believe that refugees are fleeing everything that we in the West find objectionable about Islamic society in the Middle East, from its abhorrent treatment of women to its theocratic governments. But Pew Research studies have consistently shown that more than two-thirds of Muslims in Middle Eastern countries believe that Sharia law should be the official law of the land. Among supporters of Sharia law in North Africa and the Middle East, about half say it should apply to Muslims and non-Muslims alike.

It is difficult for many highly educated Westerners to understand sincere religious belief, but when more than half of Sharia supporters in the Middle East and North Africa say they want the state to execute people who leave Islam, it might be helpful to take them at their word.

Only the most naïve idealist can believe that the cultural differences between Western countries and Islamist immigrants will not cause tension, and even radicalization, which has been especially concerning among second-generation Islamic immigrants in Europe. And there’s no screening process for second-generation immigrants.