President Trump is preparing to sign an executive order that stops U.S. admission of Syrian refugees and directs the Department of Defense and the State Department to develop plans for “safe zones” for refugees within Syria. During the 2016 election campaign, “safe zones” were frequently touted as preferable to admitting refugees. Such an approach, some argued, would keep Syrian civilians safe, while also reducing the risks that terrorists would use the refugee program to enter the United States. Unfortunately, reliance on “safe zones” holds its own troubling implications.

First of all, despite their name, “safe zones” are also not necessarily safe. Without proper protection, they can actually be easy targets to attack for those seeking to harm the inhabitants in the first place.

The Bosnian town of Srebrenica is a prime example of this. Declared a safe zone for Bosnian Muslims, it was nevertheless overrun by Bosnian Serbs who systematically killed 8,000 Muslim men and boys.

A safe zone established in Syria would therefore require U.S. protection. This would mean both instituting a no-fly zone, and establishing ground troops to protect the zones from ISIS and Syrian government soldiers. This would be a major intervention, and might require direct conflict with Syrian troops and by extension, Syria’s ally Russia.

Additionally, without viable jobs and infrastructure, refugees may flee “safe zones” anyway. There are already areas in Turkey, Lebanon, and Jordan that were relatively safe for Syrian refugees. However, the appalling living conditions of these camps sparked an uncontrolled exodus to Europe, placing strain on its southern flank. This type of regional destabilization, particularly of American allies, can lead to negative security ramifications for the United States.

Life was not that much better for those who stayed in Turkey, Lebanon, and Jordan. Because of underfunding from the international community, the burden of supporting these “safe zones” fell on countries in the region. Infrastructure in Jordan, Lebanon, and Turkey is overwhelmed. Former U.S. Ambassador Crocker—who has represented American interests in Afghanistan, Iraq, Syria, Kuwait, and Lebanon—has argued that, “left unaddressed, the strain will feed instability and trigger more violence across the region, which will have consequences for U.S. national security.”

As I have previously argued, safe zones—essentially refugee camps—can become sites of radicalization. Daniel Milton, Megan Spencer, and Michael Findley found in a 2013 study that the location of refugee resettlement is a crucial factor in their susceptibility to radicalization. Squalid conditions, lack of economic opportunities, and hopelessness can make camps fertile ground for extremist propaganda. When residents return home, they may carry the seeds of the next generation of terrorists.

So “safe zones” have their own security concerns—notably either the need for a large intervention in the region, or the possible destabilization of the region if done poorly. There are, however, additional reasons why resettling refugees instead can be beneficial for national security.

Acceptance of refugees undercuts the propaganda of terrorist organizations seeking to harm the United States. Groups like the Islamic State in Iraq and Syria (ISIS) use the argument that the United States is waging a war against Muslims to recruit. How the United States responds to humanitarian crises can either promote or counter this argument. Even accepting a relatively small number of vetted refugees can help counter terrorist propaganda.

This is why a group of bipartisan national security experts, former generals, and former cabinet members signed a letter advocating for continued refugee resettlement. Countering extremist propaganda is important in combatting terrorism, particular since recent attacks in the United States have been committed by American citizens radicalized in the United States. Banning refugees may ease a short-term security concern, but increase homegrown radicalization and attacks over time.

American acceptance of refugees also helps in the process of negotiating support from other countries. It eases the burdens on allies that are struggling with the number of refugees they have sheltered and provides the United States with a moral voice when advocating that other countries do the same.

What’s more, vetting for refugees is the most comprehensive security check out of anyone entering the United States. To be resettled, refugees must first be cleared by the United Nations. Multiple American security national agencies then undertake a background check, biometric check, interviews, and medical screenings. The process can take two years.

While there have been the occasional issues—and fixes—in the system, the record speaks for itself. Between 2001-2015, the United States accepted 784,000 refugees and only three have been arrested on charges of terrorism. Two were not planning an attack in the United States, and the third’s plan was barely considered credible. Since the 9/11 attacks, no person who has undergone the refugee clearing process has committed an attack on U.S. soil.

So, while banning refugees may assuage the security concerns of Americans, in reality it may not make them any safer. Relying on “safe zones” in war zones to protect civilians fleeing conflict may further destabilize the region, which would result in decreased security and increased costs for the United States. Both of these policies sound good and seem easy to implement. Unfortunately, these policies would be counterproductive in making America safe again.