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University of California Institute on Global Conflict and Cooperation

Conflict and Cooperation at the U.S.-Mexico Border: A Very Short History

May 03, 2023
Sarah Sears and Kevan Malone

The border wall on the Mexican side. The wall extends into a bright blue ocean, and there are names painted on the metal bars in blue, red, and black.

With recurrent migrant crises routinely in the news, and growing challenges to stem the tide of drug trafficking and other illicit flows, the U.S.-Mexico border is an emblem of national power and confrontation—but is it also a source of cooperation? Here, IGCC dissertation fellows Kevan Malone (UC San Diego) and Sarah Sears (UC Berkeley)—both historians—answer five questions on the history of U.S.-Mexico cooperation, capitalist development, and conflict along the shared  “line in the sand” at the El Paso-Juárez border and the Tijuana/San Diego border.

Borders are a projection of national power. How have the United States and Mexico sought to demonstrate their power at the U.S.-Mexico border over the years?

Sarah Sears: Migration controls and border policing are the most obvious ways in which the U.S. and Mexico have projected national power at the border, but both countries also demonstrate power through their management of the built and natural environments. Environmental infrastructure projects—including dams, fencing, and road-building—are linked by an underlying goal to control the environment. Shared landscapes and watersheds have made the U.S. and Mexico joint stakeholders—and sometimes discordant partners—in managing the natural environment. Since the mid-1800s, Mexico has negotiated for land rights and environmental justice through diplomatic channels. In the El Paso-Juárez region, for example, floods on the Rio Grande moved a tract of land, known as El Chamizal, to the north “U.S. side” of the river. In the century-long territorial dispute that ensued, Mexico advanced an anti-imperialist argument that asserted territorial sovereignty over the tract and advocated for land, water, and environmental rights for Mexican and Indigenous communities on both sides of the border.

Kevan Malone: The last one hundred years of history of the U.S.-Mexico border is largely a story of two major developments: the United States has fortified the international border, and Mexico has asserted a greater degree of national autonomy in its northern border cities. The latter has been much less linear than the former. Since the Mexican Revolution, Mexico has sought to bring its northern border region under greater national control through urban development projects. Ironically, Mexico has often relied on American capital to fund these projects. In the 1930s, during the postrevolutionary reconstruction period, Mexico built the Rodriguez Dam on the Tijuana River to provide water for domestic and agricultural purposes. Much of the funding came from tax revenue raised through American industries in Baja California, such as the Colorado River Land Company—a Los Angeles-based agricultural enterprise in the Mexicali Valley. A similar dynamic existed in the 1970s when Mexico built a concrete flood control channel on the Tijuana River to allow urban development in Tijuana’s Zona Rio (which today is home to some of the city’s most popular attractions). Much of the funding for the river channelization project came from tax revenue raised through American-owned maquiladoras (assembly plants).

The paradox is that, on the one hand, the northern border cities can be seen as monuments to Mexico’s assertion of its national autonomy since the revolution; on the other, Mexico continues to depend on American capital for development of these cities.

If the border is best conceived of as a place of movement, rather than a simple line, how has the movement—of people, goods, nature, ideas—changed over the years as the natural landscape has been built and rebuilt?

Sarah Sears: The public perception that the border is hardening, closing, and increasingly policed is mostly true, and has had major consequences, both for migrants crossing into the U.S. and for the natural environment, which has been modified to bolster U.S. border security. But commerce between the U.S. and Mexico has always demanded openness along the border to facilitate trade and the movement of goods.

Nature has often thwarted efforts to control and define the border. The borderline does not necessarily follow the logic of the natural environment—it has historically functioned more like a “line in the sand” that crosses through ecosystems and watersheds. The Rio Grande, which serves as the boundary line for two-thirds of the nearly 2,000-mile border, has challenged public officials’ efforts to control the border. Rivers move naturally over time, and even in the first few decades after the Treaty of Guadalupe Hidalgo (1848) established the boundary line, the Rio Grande’s seasonal floods shifted the riverbanks and left the location of the border up for debate.

Since the 19th century, the U.S. and Mexico have managed environmental issues along the border jointly through the International Boundary and Water Commission and its Mexican counterpart, the Comisión Internacional de Límites y Aguas. Stabilizing the boundary has taken precedence over the environmental impacts of dams and concrete channelization, which have altered the flow, temperature, and water quality in the Rio Grande. Harm to the environment has prompted criticism from environmentalists, who have been criticized in turn for overlooking migrant safety and human rights issues. Scholars have critiqued the ways in which many environmentalists have spoken out against border walls or argued for the expansion of protected wilderness spaces in the region, without acknowledging the ways in which the border landscape has become a “deathscape” for migrants through border policing and conservation policy.

Kevan Malone: Over the last 100 years, which is the period of rapid urbanization in Mexican border cities, capital has generally moved south from the United States to Mexico and working people have generally moved north from Mexico to the United States. These cross-border flows have driven the binational economy and fueled the growth of Mexico’s border cities. Tijuana’s early history is an interesting exception to this pattern. During the Prohibition era (1920–1933), Tijuana lacked adequate road and railroad connections to Mexico’s interior, so it was not a major gateway city for migration to the United States. Most border crossings were those of American tourists who went south to drink alcohol and gamble. Accordingly, San Diego border policing during Prohibition was as much about dissuading Americans from visiting Mexico as it was about preventing smuggling from the south. From 1924 to 1933, the United States enforced a curfew at the border for Americans returning from Tijuana. This policy was the result of efforts by a coalition of Protestant church groups and progressive reformers in California who hoped to discourage American visitors and starve the Tijuana saloons and casinos of their business. However, the policy had the opposite effect. Instead of deterring American visitors, the curfews incentivized American entrepreneurs to open overnight hotels in Tijuana—most notably the Agua Caliente resort (built in 1928), which attracted more visitors. American border crossings actually increased during the curfew period, and Tijuana grew significantly. Today, of course, there are many kinds of border crossings, and enforcement is no longer aimed at policing American morals.

The border river, with the U.S. on the left and Mexico on the right. Taken from the Santa Elena Canyon Trail in Big Bend National Park, Texas.

The border river, with the U.S. on the left and Mexico on the right. Taken from the Santa Elena Canyon Trail in Big Bend National Park, Texas. Photo courtesy of Jeff Vincent.

Private enterprise and capitalist development have boomed on the El Paso/Juarez and San Diego/Tijuana borders. What’s the effect been in terms of the landscape, the people, and politics?

Sarah Sears: Capitalism and private enterprise have fundamentally shaped the built and natural environments of the border region. This is particularly true in urban hubs like El Paso/Juárez, which has been a center of trade and migration between the U.S. and Mexico since the 19th century. There is a long history of real estate speculation at the border, usually to the disadvantage of Mexican and Indigenous peoples.

Since the modern border was established in 1848, American and sometimes Mexican capitalists have taken advantage of uncertainties at the border—over the legacies of Spanish and Mexican land grants, the location of the boundary line, and environmental issues such as water rights and flooding—to acquire land and resources to fuel capitalist development in the border region.

In the famous Chamizal dispute in El Paso/Juárez, different groups of developers sold plots of land under U.S. title while Mexican claimants maintained Mexican titles to the same land. Another company, the Chamizal Title Company, capitalized on the ambiguity of Chamizal titles, purchasing land at low prices, hoping the resale value would skyrocket after settlement of the dispute, regardless of which country gained sovereignty over the Chamizal tract. The dispute was not formally settled until 1963, and its unresolved nature depressed rents and led to a dearth of investment in residential and commercial real estate on the tract, even though it was adjacent to downtown El Paso.

Kevan Malone: American private enterprise has been the primary driver of Tijuana’s growth. The first boom period for Tijuana was during the 1920s and early 1930s, when alcohol was prohibited in the United States and gambling was prohibited in California. Postrevolutionary Mexico tried to bring its northern border region into the national economy. To raise tax revenue for urban development, Mexican authorities issued concessions to American entrepreneurs who opened gambling resorts and nightclubs in border cities for American clientele—just beyond the reach of U.S. law. This cross-border investment created jobs and encouraged migration from Mexico’s interior. Tijuana grew from an economically insignificant frontier town of about 1,000 people in 1920 to a budding city of over 8,000 a decade later, and tax revenue from these businesses funded construction of urban infrastructure.

A more recent driver of urban growth was the maquiladoras. In 1966, Mexico initiated its Border Industrialization Program, inviting American manufacturers to open assembly plants in northern border cities on a duty-free basis. Under this program, American companies shipped materials across the border tariff-free to assemble consumer items (automobiles, electronics, etc.) for American markets. Mexico got jobs and American companies got cheaper labor. This cross-border manufacturing economy encouraged migration from southern Mexico to the border cities, and Tijuana’s population has grown from 430,000 people in 1970 to more than 2.2 million today. Much of this growth has consisted of informal urban development, with new inhabitants building unauthorized homes on public land. Without access to running water and drainage, residents in these settlements discard their wastewater in canyons and streambeds, which rain washes into the Tijuana River, polluting American properties and parklands downstream. This has harmed cross-border relations between San Diego and Tijuana for generations. What Americans tend to overlook is that American private enterprise has been the primary driver of the urban growth that created this problem.

Effective U.S.-Mexico cooperation at the border can seem ephemeral. Are there examples where it has worked, and is cooperation generally improving or getting harder?

Sarah Sears: The United States and Mexico have a surprisingly long and largely successful history of cooperation in boundary surveying and management that dates back to the first joint mapping commission (1850s). The IBWC and CILA have cooperated extensively to maintain a stable boundary line and all of its accompanying infrastructure, including dams, irrigation canals, and border monuments. A suite of treaties ratified between the 1880s and 1970s clarified procedures for managing the boundary and reiterated both nations’ commitments to cooperation. At the federal level, the United States and Mexico have vested interests in maintaining border stability and a strong working relationship. There are more technologies, scientific knowledge, and diplomatic precedent to manage the many environmental issues that have either emerged or persisted into the present day, but there are also more stakeholders and tradeoffs to balance than there were when the border region was less populous and less central to transnational flows of capital and people.

One important thing to highlight is that individual communities and local ecosystems have at times borne the cost of the “greater good” of U.S.-Mexico diplomatic cooperation. Returning to the Chamizal case, although both governments celebrated the 1963 Chamizal Settlement as an unmitigated techno-environmental and diplomatic success, that narrative fails to account for the centuries of dispossession and exposure to environmental risk faced by Mexican claimants, in addition to the removal of several thousand working-class Mexicans and Mexican Americans in the 1960s.

Kevan Malone: San Diego and Tijuana have had no choice but to cooperate on the management of water and wastewater because Tijuana and parts of San Diego lie within the Tijuana River Watershed. After the United States conquered Mexico’s northern territories in 1848, the new international border intersected the Tijuana River, arbitrarily dividing the watershed between the two countries. The United States has exercised a great deal of power along the border since then, but the river has never recognized political boundaries—it only obeys the law of gravity. Just as the river crosses the border, so does the river’s pollution. Officials in the IBWC have engineered solutions to water and wastewater problems along the border while crossing political, cultural, and linguistic divides. But rapid and informal urban growth in Mexican border cities has made these problems more and more difficult to address.

For all the IBWC’s accomplishments, it cannot solve the basic problems underlying water and wastewater management at the border: that American private enterprise has driven rapid population growth in Tijuana and that Mexico lacks the resources to construct adequate infrastructure for handling this growth.

Historians tend to think about things in terms of what changes and what stays the same. What issue has been most emblematic of both?

Kevan Malone: One element of continuity is the hardening of the border since the 1990s. The administrations of George H.W. Bush and Bill Clinton were responding to growing public anxieties in the Southwest over the “wide-open border,” growing undocumented immigration, and demographic transformation. Border militarization has certainly not had the intended effect. Until the 1990s, undocumented labor migration from Mexico to the United States was largely concentrated in agriculture and was generally cyclical. Migrants—mostly men—crossed the border at unauthorized points near cities like Tijuana and Juarez, worked on American factory farms in the West and the Great Plains, and returned to Mexico with their earnings between growing seasons. Those who did settle permanently in the United States were concentrated in California and Texas.

This began to change with the militarization of the border in the 1990s. The enforcement strategy included enhanced border barriers and electronic surveillance in urban areas to push unauthorized migration into the desert and mountain areas, where U.S. Border Patrol agents had a tactical advantage. Ultimately, U.S. policymakers hoped to dissuade unauthorized migrants, who would theoretically be unwilling to risk their lives crossing the deserts and mountains. But rerouting migrations didn’t work—it simply made migration more difficult and dangerous, resulting in large numbers of migrant deaths. Migration also became more expensive, since migrants had to pay smugglers to lead them through rugged terrain on foot. The unintended result was that more and more migrants chose to remain in the United States rather than return periodically to Mexico. Many sought steadier work in metro areas throughout the country rather than searching for seasonal jobs in agriculture. Family members from Mexico joined them, and many started new families. So, the border enforcement strategy that was intended to prevent unauthorized immigration instead created a permanent and nationally dispersed Mexican American population.

As the geography of Mexican immigration has changed, so has the geography of anti-Mexican nativism. Until the 1990s, public calls for enhanced border barriers came mostly from California and Texas. Since the 1990s, those demands have echoed across the United States. It’s hard to imagine Donald Trump appealing to white Americans on the East Coast and in the Deep South with an anti-Mexican immigration message if not for the unintended results of border enforcement over the last 30 years. In fact, people arrested for the January 6th capitol riot tended to live in places that have experienced significant ethnic transformations in recent decades. In many of these places, the change resulted from Mexican immigration.

People camping along the pedestrian access point in Tijuana. Photo courtesy of Barbara Zandoval.

Sarah Sears: When viewed through the lens of environmental politics, tensions between local and national politics and attitudes have been a continuity since the mid-19th century. Local and regional civic activism in the border region also has a surprisingly long history, particularly in environmental and social justice/immigration issues. A lot of this cooperation is in direct response to and attempts to mitigate the consequences of federal border policy (e.g., migrant search and rescue or ecological restoration). Overall, as migration and capital flows have increased, cooperation has become more challenging at all levels.

In some ways, environmental issues are a bright spot in U.S.-Mexico governmental cooperation, at least at the federal level.

The two nations have a long history of cooperatively managing shared ecosystems, particularly water distribution, shared hydraulic infrastructure, and territorial questions.

Since the early 20th century, conservationists and environmental policymakers have advocated for binational border parklands, with proposed projects spanning the length of the Rio Grande and western land border.

These have a mixed record of success; the United States and Mexico have designated a surprising number of adjacent protected spaces in the borderlands, but they have consistently struggled to meaningfully bridge the international boundary for conservation or recreation purposes. The growing and cascading impacts of climate change are intensifying and altering U.S.-Mexico relations in numerous ways—from the challenge of allocating the Colorado River’s dwindling water, to increasing numbers of climate refugees at the U.S.-Mexico border—the environment itself is more central to U.S.-Mexico relations than ever before. More effective cooperation on environmental issues at all levels of governance would be a welcome change, but the outlook for cooperation remains extremely uncertain.