Before I built a wall I'd ask to know
    What I was walling in or walling out,
    And to whom I was like to give offence.
    Robert Frost, Mending Wall

    National frontiers are powerful inventions drawn to distinguish and separate national communities. Yet, if frontiers could be traced back to the men and women who first envisioned the line and show the line to be a human, maybe even imperial, invention instead of a destiny-endowed right or limitation, national frontiers would still be capable of provoking the greatest passions for, after all, they "wall in" the nationals while "walling out" the foreigners.

    In August 1821 the would-be republics of Central America, as part of the seceding Viceroyalty of New Spain (later Mexico), broke their colonial ties with Spain. Three years later they, in turn, separated themselves from Mexico and formed the United Provinces of Central America. The experimentation with federalism, however, did not last long, and by 1839 five independent republics had been born: Guatemala, El Salvador, Honduras, Nicaragua, and Costa Rica. Panama, the southernmost Central American nation, followed another history. As part of the Viceroyalty of New Granada (later Colombia, Venezuela and Ecuador), this sixth Central American republic separated from Colombia in 1903.

    The independence process in Central America, with the exception of Panama, resulted in republics that closely followed the territorial divisions previously established by Spain to divide its vast empire into more manageable administrative units. In the process, for example, the Intendancy of León became the independent republic of Nicaragua, and the Province of Costa Rica became the independent republic of Costa Rica. Yet, if the 1821 secession from the Spanish empire was not as prolonged and violent in Central America as in other regions of Latin America, establishing national frontiers was another matter. In the particular case of Nicaragua and Costa Rica tensions over a mutual boundary date back to July 25, 1824, when the Partido de Nicoya, the southwestern tip of the Intendancy of León, annexed itself to Costa Rica instead of Nicaragua. The annexation could be explained as a result of the Partido's strong commercial and social ties to the Costa Rican urban centers that were geographically closer to Nicoya than the leading Nicaraguan cities of León and Granada. In addition, it could also be argued that the annexation predated circulation among Nicoya's population of an articulate nationalist discourse concerning either the Nicaraguan or the Costa Rican nation. Thus, although the shield of the region nowadays called Guanacaste includes the phrase "of the nation by our own will," the Partido decision might not have been based on nationalist allegiance to Costa Rica. Even if the Nicoya annexation predated articulate nationalist discourses and was more than justified by geographical considerations, the event still redrew the late imperial administrative frontier between the Intendancy and the Province. The redrawing, in turn, challenged the mysticism surrounding the boundaries that independence movements throughout Latin America inherited and helped naturalize as rightful national frontiers.

    The 1824 annexation of the Partido de Nicoya to Costa Rica proposed the western segment of the Nicaraguan-Costa Rican frontier. Tracing the eastern part, however, has proved a rather slippery task, for caught in the middle of the issue is not land, but water. The disputed water is that of the San Juan River flowing east from Lake Nicaragua and running between the two Central American nations all the way to the Caribbean Sea. This river has been a source of constant tension in Nicaraguan-Costa Rican relations at least since the mid-19th century, when British and North American firms searched for a waterway connection between the Atlantic and Pacific oceans. Confrontations over the San Juan River, almost reaching the point of an open warfare, made it clear to the two young republics and the interested international community that frontier differences had to be settled before an interoceanic canal could be realized. The canal was eventually constructed in Panama by 1914. Nonetheless, the presidents of Nicaragua and Costa Rica, mediated by an official delegate from the republic of El Salvador, had early on attempted to settle the dispute by signing the Cañas-Jerez Treaty in April 15, 1858.

    The Cañas-Jerez Treaty divided the national territories of Nicaragua and Costa Rica through an imaginary boundary line that followed the San Juan River from the Caribbean Sea to Lake Nicaragua near the Pacific coast. In fact, the eastern third of the line was traced over the river's southern banks while the remaining two-thirds extended two miles south of the bodies of water. As the tracing of the line suggested, the treaty assigned sovereignty over the San Juan River to Nicaragua but still granted navigational rights through the eastern third to Costa Rica. The treaty further stipulated that both nations were equally responsible for upkeep and defense of the shared waterway. In the event that conflict developed between the two Central American republics, the treaty forbade any kind of hostile activity from being carried out in the river or in the lake. The frontier waters would, at least theoretically, become a neutral zone. The prohibition of hostile acts also applied to times of peace. Thus, the treaty sought to create a frontier that served as a buffer zone capable of absorbing pressures exerted from north and south of the border. On the one hand, any hostile party would have to circumvent the San Juan River and Lake Nicaragua in order to reach its neighbor. Such a circumvention implied traveling through a narrow strip of land west of the lake or through either the Caribbean Sea or the Pacific Ocean. On the other hand, making the same bodies of water a neutral zone for which both countries were responsible offered common ground, or water, that could keep dialogue flowing in times of peace and, more importantly, in times of difficulty.

    The San Juan River, however, has not become the conflict-free zone envisioned by the makers of the Cañas-Jerez Treaty. On the contrary, 148 years later the shared tract of river is a disputed militarized zone. The problem has markedly escalated since July 15, 1998, when Nicaraguan President Arnoldo Alemán (1997-2001) forbade armed Costa Rican policemen to navigate the river. The prohibition was followed by seven years of unfruitful diplomatic discussions culminating in a lawsuit against Nicaragua submitted by Costa Rica on September 27, 2005 to the International Court of Justice in The Hague. Whatever hopes the Costa Rican government might have in resolving the particular issue through the International Court, it is unlikely that the Court's ruling will successfully resolve the Nicaraguan-Costa Rican conflict over the San Juan River because the frontier problem runs deeper than divergent readings of the Cañas-Jerez's stipulations. In the end, the dispute over whether Costa Rican policemen infringe Nicaragua's national sovereignty by navigating the river in possession of their commissioned side arms is but the tip of the iceberg.

    The banning of armed Costa Rican policemen from the San Juan River was ordered by President Alemán only days after members of different Nicaraguan frontier communities expressed a desire to annex their region to Costa Rica. This was interpreted by many at the time as a call for attention rather than an actual threat. President Alemán, however, probably realized the danger of such a secessionist outburst coming from poor communities that, as their Costa Rican counterpart, have economic and quality-of-life indicators significantly lower than their respective national averages. The bleak situation partly reflects the isolation faced by these frontier settlements, many of which are not connected by roads to their larger national communities and must therefore be reached by air or water. The isolation, not to say abandonment, experienced on both sides of the border directs the everyday lives of the inhabitants towards the shared waters of the San Juan River. This has resulted in the creation of a transnational community linked through familial, cultural, and economic ties that have flourished across the frontier line dividing Nicaraguans and Costa Ricans.

    This emphasis on a transnational community should not overshadow the marked differences. Among other variables, Costa Rican frontier communities generally have access to basic infrastructure denied to their Nicaraguan neighbors. In fact, the lack of basic services such as clean water and electricity was identified by local newspapers as one of the main causes of the secessionist outburst. To further understand secessionist expressions, the list of infrastructural shortcomings must be broadened to include not only roads, but also water, electricity, health services, schools, and government services in general. In addition, there is limited access to national newspapers, television channels, and radio stations, which transform Nicaraguan communities into consumers of Costa Rican media. The absence of government agencies and other institutions and media that help in the education and formation of national citizens has arguably alienated these Nicaraguan frontier populations more deeply from their larger national community than the lack of roads. President Alemán must have had this kind of alienation in mind when he quickly intervened in the frontier zone through promises of better infrastructure and the banning of armed Costa Rican policemen. Current Nicaraguan President Enrique Bolaños must have had these same concerns when he recently ordered the posting of soldiers along the San Juan River.

    Since September 2005 President Bolaños has undertaken assertive measures to demonstrate the Nicaraguan state's presence in the frontier zone. The most visible measure has probably been the patrolling and stationing of armed soldiers in and along the banks of the San Juan River. The Nicaraguan government has defended the increased military presence as necessary to protect its national territory, especially against what some have called Costa Rican expansionism. While Costa Rica abolished its armed forces in 1949, Nicaraguan fears are not totally unfounded. As recently as 1995 a Costa Rican citizen argued in the United Nations for the independence of a Nicaraguan strip of land he planned to rule. While this independence scheme failed, recent events have brought back memories of the Partido de Nicoya's annexation to Costa Rica, which is more frequently interpreted by Nicaraguans as the usurpation of national territory. The question to ask, nonetheless, is what exactly is at stake in the San Juan River that would justify this confrontation of two neighboring nation-states. The answer, some say, has not changed much in 160 years as it still lies in the possibility of an interoceanic canal. Politicians on both sides of the border possibly dream of a canal, but the Nicaraguan-Costa Rican tension is further fed by nationalisms predicated on the unproblematic separation of nationals from foreigners. In the case of Costa Rica, nationalism is frequently based on a discourse of Costa Rican exceptionality, on how Costa Rica evolved into a pacifist and ecology-friendly nation surrounded by violent Central American ones. Such a nationalist discourse has given rise to xenophobic sentiments directed against Central Americans but, most precisely, against Nicaraguans. Such an anti-immigrant sentiment, which is not necessarily widespread throughout the Costa Rican population, has materialized in scattered episodes of violence committed against members of the Nicaraguan community on Costa Rican soil. The incidents, in turn, have given ground to Nicaraguan critiques denouncing the Costa Rican state and citizenry, despite its image of pacifist democracy, as a violently discriminatory nation.

    One of the main problems in Nicaraguan-Costa Rican relations is the seemingly contradictory stances taken by politicians on both sides of the frontier. Depending on the forum, politicians can either assume a neoliberal discourse underlining the urgency for Central American regional integration, or express and endorse measures of an aggressively xenophobic character. For example, the current Costa Rican administration headed by President Abel Pacheco endorsed negotiation of the Central America-United States Free Trade Agreement (CAFTA), while ratifying stricter immigration laws that, for example, harshly penalize employers of illegal immigrants that are basically understood in the Costa Rican context as Nicaraguans. In other words, the Pacheco administration has encouraged freer, if not totally free, movement of technology, capital, and commodities while trying to restrict the movement of people. Nicaragua, on the other hand, has also engaged the CAFTA negotiations while raising, or at least threatening to raise, tariffs on Costa Rican products and shipments across Nicaraguan territories. Meanwhile, citizens of towns such as El Castillo and Crucitas could ask that, instead of disputing over expensive lawsuits and free trade agreements, their Nicaraguan and Costa Rican governments work together to encourage more equal development across the frontier area and thus help ease tensions over the shared waters of the San Juan River.

    National frontiers are powerful if rather unstable inventions, acutely so if they are drawn over running water. It could be that lines traced over water remain too fluid inventions to efficiently work as fixed boundaries. Maybe a line drawn over a river either drowns or remains too malleable as it travels downstream. The snakelike movement could appear to bring the frontier to life, tempting the casual dwellers to transgress and jump the line like people have been doing in the San Juan River for almost 200 years. So in the end, maybe the answer to Robert Frost's question is that only good solid fences make good neighbors because otherwise the apples feel tempted to cross over and mix with the cones under the pines.

    Marie Cruz Soto is a doctoral candidate in Latin American history at U-M currently living between Puerto Rico and Costa Rica while working on her dissertation.