Over the past decade, migration has become an increasingly complex and global phenomenon, with significant implications for national security, humanitarian obligations, and international relations. The sheer scale and diversity of recent migration flows have underscored the limitations of unilateral border enforcement.
As migrants originate from more varied regions and traverse multiple countries, the challenge of managing irregular migration has evolved from a localized border issue into a multifaceted policy concern requiring cooperation between nations.
While immigration has traditionally been seen as part of the domestic policy agenda in the United States, it, almost by definition, involves foreign policy, too. Managing international migration for the long term will require increasing use of foreign policy tools, perhaps even more than domestic ones.
The executive branch should prioritize international cooperation and capacity-building with countries of origin, transit, and destination as an important part of its migration management efforts:
- The U.S. Department of State and Department of Homeland Security should work with regional allies to coordinate law enforcement efforts targeting criminal smuggling organizations.
- The U.S. intelligence community should pursue better intelligence sharing with countries along migration routes to promote early recognition of large flows and allow for the preparation of responses along the route.
- The U.S. Departments of Commerce and State should encourage private sector investment and work with regional allies to reduce economic barriers to address the root causes of migration.
- The Department of Commerce, Department of Homeland Security, and Department of State should collect and publish robust data demonstrating the effectiveness of international policies and investments to manage migration.
The last decade has upended years of investment in border security by the United States in personnel, technology, and infrastructure as well as border barriers. Because of political gridlock, Congress has not enacted legislation to address the domestic aspects of immigration law. Administrations since the Obama Administration have undertaken efforts to engage international partners to address changing migration to the United States, with varying degrees of success.
This is also happening at a time when migration crises in other parts of the world, including Europe and Australasia, have challenged the post-World War II international consensus around refugee processing and territorial asylum. Consequently, many countries have unilaterally limited this means of seeking protection, and the issue has become an important one in international and multilateral conversations. For example, U.S. officials had meetings with representatives of several other countries on the sidelines of the 2025 United Nations General Assembly to discuss the idea of overhauling the U.N. Refugee Convention of 1951 and its 1967 protocol – the basis of current international refugee and asylum laws, including in the United States.
Changing migration patterns: Populations, nationalities, and routes
The changing populations, nationalities, and routes taken to reach the U.S. southern border have placed unprecedented burdens on the U.S. immigration and asylum system, border enforcement personnel and facilities, and entry processes and infrastructure.
Populations
Traditionally, most irregular migrants at the U.S. southern border were from neighboring countries, overwhelmingly Mexico, and were primarily single adults. They attempted to evade detection at the border to enter and work illegally in the United States, often with the intent of returning home in the future, rather than remaining permanently in the United States.
Migration from Central America had at least since the 1980s constituted a minority portion of illegal entries at the U.S.-Mexico border. But beginning during the Obama Administration, an increase in migrants from the Northern Central American countries of El Salvador, Guatemala, and Honduras, particularly unaccompanied children, created challenges for the U.S. border infrastructure and processes. Since the mid-1990s, border officials extensively used the process of expedited removal as the primary means of rapidly deporting those who arrived illegally without an immigration hearing, at first for those arriving at ports of entry and later for those arriving between ports of entry.
Immigration law has two major exceptions to expedited removal:
- Unaccompanied minor children from countries other than those contiguous to the United States (i.e., Mexico or Canada).
- Individuals who express a “credible fear” of return to their country as a precursor to applying for asylum.
During the first Trump Administration, and especially in the Biden Administration, migrants arriving at the border utilized both exceptions to gain entry to the United States while awaiting hearings in immigration courts to determine if they could avoid deportation. The large number of such arrivals resulted in historic backlogs in immigration court, topping 3 million cases in 2023, meaning years of waiting for a case to be heard.
Nationalities
At the same time, a rise in arrivals from South America, the Caribbean, Africa, and Asia put further strain on the system. This reflected global displacement trends and changing migration drivers.
Effecting deportation to more distant countries created logistical and diplomatic challenges for the U.S. government. Logistical hurdles include arranging air transport to countries as far away as Africa and East Asia, with a system mostly accustomed to using ground transportation for deportations to closer geographic locations.
On the diplomatic front, deportees who could not be returned to their country of nationality because of delays or refusals by their government could only be sent to a third country if that country agreed to receive them, creating the need for new diplomatic agreements.
Routes
The third major shift is in the routes taken to reach the border. Most arrivals to the land border traveled through Mexico on foot, or sometimes dangerously rode atop freight trains from the southern part of the country. However, this period also saw an increased use of diverse routes – sometimes crossing multiple countries and even oceans – to reach the United States.
This resulted in the growth of transnational criminal smuggling organizations acting much like illegal tour agents, offering guides, transportation, and escorts to the border for those able to pay their extortionary fees. The multiple borders crossed in these journeys also meant that efforts to prevent this migration required many countries working together. The increased diversity in nationalities and migration routes also created language barriers, differing asylum claims, and varying needs for humanitarian protection.
While the current situation at the border is much muted from recent years, now is an opportune moment to take stock of lessons learned.
The realities of modern international migration underscore the need for adaptive, multifaceted policy responses. With Congress so far unwilling to enact legislative changes to the immigration laws to address these challenges, presidents have increased efforts to mitigate the impact of the crisis through various means, including foreign policy – the realm granted to the executive branch in Article II of the Constitution.
U.S. policy responses: Tactics and tools across administrations
Recent U.S. administrations have experimented with a range of policy tools aimed at managing irregular migration and securing the border. These tactics have included both unilateral actions and collaborative efforts with other countries, reflecting the interconnected nature of migration flows.
Port of entry metering: Metering – which limits the number of asylum seekers processed at official ports of entry each day by physically blocking the actual border line to prevent access to U.S. territory was implemented in various forms by the Obama, Trump, and Biden Administrations. While intended to manage capacity, this approach typically led to bottlenecks and humanitarian concerns at the border.
Migrants waiting their turns to cross the border ended up staying in border cities in northern Mexico, where they put strains on local economies and migrant services and were targets for criminal activities such as kidnapping and extortion. Mexican authorities often kept journals of names with those on the “waiting list” and worked with U.S. officials to limit access to the physical border.
Remain in Mexico (Migrant Protection Protocols): Initiated during the first Trump Administration, this policy required certain asylum seekers, who had undergone initial processing at a U.S. port of entry, to wait in Mexico for their U.S. immigration proceedings. The approach was controversial because of concerns about safety and due process. Both its implementation and subsequent termination have been subject to legal and diplomatic negotiations. The government of Mexico allowed Spanish-speaking non-Mexican nationals from Northern Central America to be returned to Mexico from the U.S. border, although no formal agreement was signed to this effect.
CBP One mobile application: The CBP One app was introduced under the Biden Administration to facilitate appointment scheduling at metered ports of entry. The aim was to streamline access to asylum processing and reduce irregular crossings – essentially taking over the waitlist from Mexican authorities. Technology access issues and limited system capacity reduced its effectiveness for many migrants.
Third-country deportation and detention: The United States has, at times, coordinated with countries such as Mexico to receive deported Central American and Caribbean nationals and with other countries for detention and removal of extra-continental migrants. Policies like the Asylum Cooperative Agreements (during the first Trump Administration) and the expansion of the Safe Third-Country Agreement with Canada (during the Biden Administration) reflect efforts to share responsibility for migration management. During the second Trump Administration, bilateral agreements to receive third-country deportees have been made with El Salvador, Panama, and countries outside the Western Hemisphere, including the African countries of Rwanda, Uganda, Eswatini, and South Sudan. Talks with as many as 50 countries may be underway, according to recent reports.
These approaches have generated significant debate regarding their effectiveness, humanitarian impact, and implications for U.S. international relationships, as well as litigation: Each of these policies has been the subject of court cases, including some that have gone to the U.S. Supreme Court, although all are still in some stage of argument or appeal.
Setting aside for the moment the legality of these policies as a matter of U.S. immigration law, they reflect two major shifts from traditional border operations: limiting access to the territory as a means of curbing asylum applications and third-country repatriation.
Both Republican and Democratic administrations crafted these policies in an attempt to prevent border authorities from being overwhelmed, and they remain central to certain legislative efforts to revise the legal framework for asylum at the border as well. Over the last five years, dozens of bills, some bipartisan, have been introduced to limit asylum at the border and mandate Remain in Mexico and other policies, but none has been enacted.
International engagement: The role of foreign partnerships in migration management
Given the transnational nature of contemporary migration, the United States has increasingly engaged foreign partners in efforts to manage migration flows heading to its southern border. This has occurred through diplomatic agreements, development assistance and other foreign aid, and operational cooperation, among other channels. It reflects an increasing recognition that migration challenges cannot be addressed by unilateral border enforcement alone.
Here are some examples of recent international engagement on migration:
Cooperative agreements: The Asylum Cooperative Agreements (ACAs) with Guatemala, Honduras, and El Salvador during the first Trump Administration sought to redirect or return certain asylum seekers arriving in the United States to these countries for processing. The Safe Third-Country Agreement with Canada, originally signed in 2004 during the George W. Bush Administration and later expanded in 2023 during the Biden Administration, allows the United States and Canada to return asylum seekers to each other, whether these asylum seekers crossed at a port of entry or between ports of entry. During the first Trump Administration, unsuccessful efforts were made to secure a safe-third-country agreement with Mexico. These types of agreements, although allowed under international treaties regarding refugees, have also been subject to litigation in the United States and in Canada. The Trump Asylum Cooperative Agreements were ended during the Biden Administration, but the second Trump Administration signed new agreements with Guatemala and Honduras similar to those previously in place. At the same time, it negotiated a new third-country deportation agreement with El Salvador and many other countries.
Regional initiatives: During the Biden Administration, the United States hosted the 2022 Summit of the Americas and negotiated a regional agreement with 21 countries in the Western Hemisphere called the Los Angeles Declaration on Migration and Protection. Although not a binding treaty, the agreement included commitments to expand legal migration and protection pathways, combat human smuggling, and support displaced populations and their host communities. The second Trump Administration has moved away from the declaration’s framework in favor of the bilateral agreements described above through several executive orders. The Trump Administration has not continued these ministerial meetings, which the Biden Administration participated in through the president’s term of office.
Development, law enforcement, and humanitarian assistance: Different administrations have used foreign aid in various ways to help with managing migration. Both Trump Administrations have used such foreign aid, or the threat of withholding it, as leverage in negotiations on bilateral agreements on migration. Additionally, the Trump and Biden Administrations used foreign law enforcement assistance to help countries improve their own border management and enforcement processes. The Biden Administration invested in international organizations such as the U.N. Commission on Human Rights and the International Organization on Migration to assist countries in the region in providing integration assistance to displaced populations in their countries – as well as to support the asylum processing capacity of these countries, especially Mexico. The Biden Administration also emphasized the importance of development and investment in the region to address the so-called “root causes” of migration – such as violence, poverty, and governance challenges in origin countries – although the effectiveness of these efforts was limited during Biden’s term.
Key findings and recommendations
Recent experiences offer valuable lessons for policymakers seeking to manage migration effectively while upholding humanitarian and legal commitments. The evolving landscape of global migration demands adaptive, coordinated policy responses that extend beyond the territorial border. The U.S. experience demonstrates both the challenges and opportunities of engaging foreign partners in migration management.
The following lessons should be taken into account by both the executive branch and Congress in future policymaking for international migration management:
- Unilateral border enforcement measures may offer short-term relief but are insufficient to address the underlying drivers and transnational dynamics of migration. Border control is always subject to fluctuation.
- International cooperation, while essential, requires careful negotiation, mutual trust, and sustained investment to ensure that partner countries have the capacity and resources to fulfill shared responsibilities over time.
- Policy tools should be evaluated not only for their deterrence effect but also for their humanitarian impact and legal compliance. Drastic changes from one administration to another will likely result in large changes in migration patterns as migrants and smuggling organizations adapt.
With these lessons in mind, future presidential administrations should consider these policies:
The U.S. Departments of State and Homeland Security should work with regional allies to coordinate law enforcement efforts targeting criminal smuggling organizations.
Border management is important to every country along the migrant transit routes, not just the United States. Transnational criminal organizations smuggling humans make the entire hemisphere less safe. The United States should work closely with our regional allies to provide a coordinated, robust response to hold these organizations accountable for the suffering they cause.
- The United States should work closely with our regional allies to provide a coordinated, robust response to hold these organizations accountable for the suffering they cause.
- U.S. law enforcement cooperation, via the Department of Homeland Security, Department of Justice, and Department of State, should ensure that enforcement measures uphold humanitarian standards and legal obligations.
- Congress should continue to provide oversight of any law enforcement cooperation agreement with another country to safeguard human rights and legal obligations.
The U.S. intelligence community should pursue better intelligence sharing with countries along migration routes to promote early recognition of large flows and allow for the preparation of responses along the route.
Migration in the Western Hemisphere hasn’t ended, even though the number of people arriving at the U.S. border has slowed significantly. There will be another catalyst that drives migration around the region. The United States and our allies must commit to sharing intelligence on movements of people so we can work together to promote safe pathways to permanent resettlement rather than letting people fall victim to smugglers.
The Departments of Commerce and State should encourage private sector investment and work with countries where migrants originate to lower barriers to economic opportunity.
Migration can be the result of political instability, persecution, gender-based violence, or lack of public safety. For many migrants, outmigration is also a result of a sustained lack of economic opportunity. The origin countries for many migrants have structural barriers that inhibit foreign direct investment, such as strict regulations on business structures, lack of governance or rule of law to enforce contracts, and potential for nationalization of assets. Technological barriers can be reduced, too, to improve countries’ competitiveness in and access to the global economy. Working cooperatively with countries to lower these barriers has the potential to reduce the longer-term incentives to migrate.
The State Department and other agencies involved with disbursing foreign assistance funds to address migration should provide regular reports to Congress on the effectiveness of programs receiving foreign assistance funds and the robust outcome-focused metrics used to determine efficacy.
Accountability is important to ensure that any program that the U.S. government funds is using American taxpayer dollars to promote real, sustainable solutions. U.S. government agencies should be compelled to provide reports demonstrating actual outcomes of foreign assistance programs designed to manage migration flows and address the reasons why people migrate. For example, reports could measure an increase in participation in the formal economy, or a demonstrated reduction in violence such as a lower murder rate or a reduction in outmigration from select countries.
Conclusion
Future administrations can benefit from adopting a balanced approach that integrates border security, international engagement, and long-term development strategies. Transparent monitoring and evaluation mechanisms, as well as ongoing dialogue with civil society and international partners, are crucial for refining migration management policies.
Executive branch actions are inherently vulnerable to both political backlash and legal challenges, but the executive branch plays an outsized role in the foreign policy aspects of immigration. While Congress should take the lead in developing or changing laws to support border enforcement and immigration reform, the executive branch should utilize the policy tools outlined to ensure the United States works proactively with our allies to manage regional migration.
