Aristide Zolberg coined the term “remote border control” in 1997 to describe the system of issuing visas at consulates abroad and screening passengers at European ports of embarkation. These mechanisms devised in the late nineteenth and early twentieth centuries created for the first time a permanent means to select migrants from abroad before they could reach an intended destination like the United States. Scholars from neighboring disciplines and traditions have developed concepts similar to “remote control,” such as policies of “non-entrée,” shifting migration control “out” from state borders, “deterritorialized” control, and “externalization.”

Zolberg observed that regulating migration at the port of embarkation abroad “is now so familiar that we tend to underestimate its radically innovative character and its fundamental importance in regulating world-wide movement.” In Refuge Beyond Reach: How Rich Democracies Repel Asylum Seekers, I show how modern remote control has become a pervasive global system. An architecture of repulsion is designed to keep out the unwanted. Many of these policies were developed before the advent of the international refugee regime. Other structures specifically target people seeking asylum to prevent them from reaching a territory where they can avail themselves of non-refoulement: the promise that refugees will not be returned into the arms of their persecutors. Even states that generally observe the principle of non-refoulement try to prevent asylum seekers from entering spaces where they will be able to enjoy effective legal representation and access to an independent appeals process if their case is first denied. Regardless of the intentions of government actors when particular policies were put into place, the cumulative effect of the architecture of repulsion is to systematically shut down most paths to asylum.

Caging keeps refugees in their countries of origin or camps in other countries. Governments in the Global North work with the UNHCR and the International Organization for Migration to fund refugee camps and centers for asylum seekers, usually in countries neighboring conflict zones, and to repatriate refugees who are willing or can be made to return home. Refugee camps are core elements in the architecture of protection as well as repulsion. They combine logics of humanitarianism, to provide basic services such as shelter and food, as well as logics of surveillance and control, to keep refugees from moving to the Global North. Most caging takes place in the Global South, in a “grand compromise” in which the Global North pays southern neighbors to keep refugees away from the North in return for limited resettlements and financial aid. Caging involves techniques that fall along a continuum of coercion. The softest is publicity campaigns to convince potential asylum seekers to stay home. Designating a country of origin as “safe” is another method, which governments used to create a rebuttable presumption that asylum seekers of particular nationalities are not refugees. The hardest approach to caging is military intervention.

A virtual dome over national territories has become a primary technique of mobility control that restricts access via airspace. The anchors of the dome are consulates across the planet where diplomats or their deputies decide whether to issue visas allowing travel to particular destinations. The global visa regime quietly keeps asylum seekers away from the Global North. Visa requirements often have a “domino effect” as governments race to prevent the entrance of asylum seekers barred from other countries. Sanctions against airlines that allow passengers to board without visas and provisions that make the airlines responsible for transporting rejected passengers back to the point of embarkation effectively deputize airline check-in agents to prevent asylum seekers from ever getting on an aircraft. Liaison officers from rich countries are stationed abroad to advise the airlines whom to prohibit from boarding. The United States has even established pre-clearance operations in fifteen foreign airports where passengers must clear U.S. passport control but are not allowed to ask for asylum.

Governments of destination countries use their neighbors as buffers to repel unauthorized migrants, including asylum seekers. Common techniques include running joint paramilitary patrols and funding and training to enhance control capacity. Legal tools include readmission agreements, in which the buffer states agree to take back rejected asylum seekers who passed through their territory, “safe third country” designations that deny asylum to applicants who passed through a named buffer country where they will not be persecuted, and pressure on buffer states to criminalize irregular migration.

Countries with maritime borders use the sea as a moat to keep out the unwanted by intercepting boats carrying passengers without visas. The European, Australian, and U.S. governments have all used the high seas as a zone to intercept asylum seekers and keep them away from their coasts. When the U.S. Coast Guard intercepts people on boats sailing from Caribbean islands, it engages in the most extreme form of the externalization of borders. These interceptions control both entry to the United States and exit from Cuba or Haiti to any other country. Such policies turn an island into a cage.

Finally, governments design fortifications at the entrance to their territory where special rules apply. In medieval times, castle builders often constructed a barbican outside the main walls as an outer defense that was not part of the castle proper. In modern times, governments have created “anomalous zones” at the entrances to their territory that function as barbicans. These zones create the fiction that asylum seekers are not physically present in the state’s territory, or at least not fully within its walls, where they would have greater rights, like access to lawyers and independent review of their appeals.

This medieval landscape of domes, buffers, moats, cages, and barbicans prevents the unwanted from finding refuge. A range of deterrence methods — first designed to keep out Jews fleeing the Nazis in the 1930s and 1940s — have now evolved into a pervasive global system. Remote controls have intensified and spread since the 1980s, with the basic set of techniques in place across North America, Europe, and Australia by the early 2000s. What is new about the system of contemporary remote control is that it involves governments reaching out beyond their territories in extensive, routine collaboration to track and deter millions of individuals and particular groups trying to cross borders. Governments of wealthy countries share with each other ideas about the most effective practices. They use funding, training, and information sharing to build up the capacity of other states to control transit and exit. Each element in the system interlocks with others. For example, visa policies are only effective at keeping the unwanted away if transportation companies act on behalf of states to check documents. Maritime interceptions are only effective at deterrence if intercepted travelers are taken to spaces where they have fewer rights than if they reached destination countries.

As refugees look for new paths to safety, governments of countries in the Global North continue to extend a worldwide system of remote controls to try to keep them and other unwanted migrants away from their borders. The concept of “remote control” could be misleading if taken too literally, however. States do not have the capacity to turn migration flows on and off with the push of a button. Once a movement is channeled by social networks or a developed people-smuggling industry, it is especially resistant to government intervention. Migration control may be the dream of all states, but it is a dream that is never fully realized.

David Scott FitzGerald is Theodore E. Gildred Chair in U.S.-Mexican Relations, Professor of Sociology, and Co-Director of the Center for Comparative Immigration Studies at the University of California San Diego. His research analyzes policies regulating migration and asylum in countries of origin, transit, and destination.