The idea of creating temporary “safe zones” in the Middle East as a way of dealing with the Syrian refugee crisis has gained support among policymakers. Ben Carson recently visited a refugee camp in Jordan and claimed that the refugees had an “intense desire to return to their country.” Swiftly restoring refugees to their former homes may be attractive from a short-term security point of view. But it’s not easy to do, and it may be unwise to try. In the longer term, repatriation can renew the sectarian conflicts and economic pressures that sparked conflict in the first place, potentially resulting in a new round of violence and humanitarian disaster.

A report from the United States Institute of Peace (USIP) on the history of refugee repatriation explains that a loss of infrastructure, dramatically reduced economic opportunity, and heightened social tensions after war often made it hard for refugees to return successfully to their former homes.

In Bosnia, refugees who wanted to return home, as well as those who were forced to return, found their old houses reduced to rubble and local housing stocks destroyed. Others found their vacated homes occupied by other displaced people.

It can be difficult for repatriated refugees to make a living in economies devastated by war. In the 1980s, Afghanistan’s agrarian economy was uprooted by waves of refugees fleeing the hotspots of the war with the Soviet Union. Refugees would flee and return, only to flee again, leaving established networks of production, trade and employment in shambles.

Areas of conflict often need structural reforms and stability measures—including the presence of peacekeeping troops—to rebuild what was lost to war. In Bosnia, it took over a decade and $15 billion in assistance to rebuild.

Another problem with repatriating refugees is the tense social and political climate created by putting a country back together after conflict. Regardless of how diverse cities and regions once were, returning refugees are often separated from people of other ethnicities and sects. Neighborhoods that were mixed before a war often become segregated afterwards. USIP found this to be true in Bosnia, Iraq, and Burundi.

It’s likely that this type of ethnic separation has fueled the ongoing sectarian problems in Iraq. Sectarian groups often materialize in the wake of conflict to provide protection and basic necessities to their relevant communities, heightening existing distrust and antagonism between ethnic and religious groups. In Burundi, a cease-fire collapsed due to disputes over land and other unresolved social problems. According to the United Nations High Commissioner for Refugees, similar problems sparked the resumption of violence in Liberia during the late 1990s and early 2000s.

These obstacles to successful repatriation must be kept in mind when policy-makers debate how best to respond to the Syrian refugee crisis. A simple desire to return the status quo ante is not enough to reassemble a broken country. If the U.S. wants to pursue a policy of refugee camps and repatriation, we need to realize that the long-term costs will be much higher than the cost of funding temporary camps, and that repatriation can heighten toxic social dynamics that may led to new wars and new refugee crises.

It makes more sense to allow refugees to resettle where they can find jobs, education, and economic development. They can then return home when Syria is stabilized, and rebuilding is done. Then, when they do go home, refugees will have incomes, savings, and skills that can be assets to their communities. In contrast, refugees stuck in camps for years will return penniless with rusty skills, needing the sort of help recently war-torn communities cannot easily provide.

Some refugees will never be able to go back. When ethnic or religious minorities flee, members of the dominant group often take over their abandoned jobs and social roles. Returning minorities may find themselves in an even more dire and marginalized position, and risk restarting the conflict that caused them to flee in the first place. The longer a conflict takes to resolve, the harder it becomes to repatriate refugees, whether they’ve been resettled in camps or other countries. The Syrian civil war, having raged for four years now, will leave the country in very bad shape for returning refugees.

Refugees shouldn’t be discouraged from returning home, but the harsh reality is that it’s dangerous to pressure them to do so. History has shown that repatriating refugees can result in high long-term costs and grave risks. The U.S. and the Europe should instead allow refugees to settle where they can find work and peace. If the time comes for them to return home, they will be better prepared for the rebuilding that they will need to do.

Op-ed by Joshua Hampson; originally published in the Huffington Post