Peaceful Borders and Illicit Transnational Flows in the Americas

This article introduces an analytical framework to explain the coexistence of peaceful borders and illicit transnational flows as evidenced by drug trafficking, human trafficking and smuggling, weapons trafficking, and terrorism in the Americas, a region characterized by international peace, domestic peace, and regional integration. Under the assumption that peaceful relations among neighboring countries enable the incursion of transnational nonstate actors across their borders, the article poses this main question: Under which conditions might peaceful borders enable illicit transnational flows? There is much more variance in the incidence of these illicit transnational flows across borders than in the existence of international peace. The article examines two major variables: the degree of governance and institutional strength of the bordering states; and the prevalent socioeconomic conditions of the bordering states. Resumen En este articulo introducimos un marco analitico para explicar y entender la coexistencia de fronteras pacificas y movimientos transnacionales ilicitos, como por ejemplo el trafico de drogas, el trafico y contrabando de personas, el trafico de armas, y terrorismo, en las Americas. Para ello, tomamos como punto de partida el argumento que relaciones pacificas entre paises vecinos facilitan, bajo ciertas circunstancias, la incursion de actores no-estatales transnacionales a traves de sus fronteras. La pregunta principal que nos formulamos en este articulo es: Cuales son las condiciones a partir de las cuales las fronteras pacificas permiten movimientos transnacionales ilicitos? Se refleja una mayor variacion en la incidencia de estos movimientos transnacionales ilicitos a traves de fronteras que la existencia de paz internacional. Por lo tanto, examinamos dos variables importantes: (1) el grado de gobernanza y fortaleza institucional de los paises vecinos; y (2) las condiciones socio-economicas que prevalecen en los paises vecinos.


Introduction
Scholars and practitioners of international relations have increasingly pointed out existing linkages between armed conflicts and different types of criminal and terrorist activities in many regions of the world (see Andreas 2011). Their underlying logic has been that illicit transnational activities might thrive under conditions of violent conflicts and war. By contrast, in this article we address the analytical puzzle and the empirical evidence according to which peaceful borders, under certain conditions, enable and enhance transnational illicit flows. Peaceful borders define the normal situation in the international relations of countries that sustain diplomatic relations, usually sharing open, demilitarized, and soft borders (see Newman 2005, 335). Many times these illicit flows are facilitated and carried out by transnational criminal and terrorist nonstate actors engaged in drug trafficking, human trafficking and smuggling, and weapons trafficking.
As in other parts of the world, the terms of the security debate in the Americas have shifted dramatically over the last thirty years. Since the end of the Cold War many of the countries of the Western Hemisphere, like elsewhere in the world, have confronted new types of security challenges that they have been hard-pressed to tackle effectively. Traditional issues of war and peace have become irrelevant to cope with "intermestic" (international and domestic) problems of national and international security (see Kacowicz and Mares 2016, 25). The end of the Cold War brought with it a more permissive strategic environment that allowed many states to focus on a broader menu of interests and challenges in their foreign policy agendas, such as the global "war on terror" or the "war on drugs." It also brought new actors into the forefront of the security environment, including the proliferation of transnational violent nonstate actors (VNSAs). At the same time, this new post-Cold War era exposed the fragility and institutional underdevelopment of many of these states in terms of feeble governance that failed to address issues of human security, crime, and domestic violence (see Felbab-Brown 2017, 2;Fried, Lagunes, and Venkataramani 2010;Carreras 2013;Wolf 2010;and Contreras 2014).
Furthermore, the concept of security has broadened since the end of the Cold War. An expanded concept of security allows us to focus on the so-called new security threats and risks emerging with the intensification of globalization and regionalization processes. For instance, according to the Managua Declaration of 2006, issued in the Seventh Conference of the Ministers of Defense of the Americas, "terrorism, drug trafficking, human trafficking, organized crime, money laundering, corruption, and the proliferation of small arms and light weapons all pose significant threats to the security of the American countries" (quoted in Kacowicz and Mares 2016, 26; see also Pion-Berlin and Trinkunas 2007). All these threats transcend state jurisdictions, which are transnational by nature, and they are linked to both licit and mostly illicit activities of VNSAs across international borders due to the prevalence of international peace (absence of war and presence of diplomatic relations) in most regions of the world.
This article addresses the linkage between the existence of open borders and the presence of security threats emerging from the proliferation of transnational illicit flows conducted by VNSAs under certain conditions (see Vogeler 2010;and Payan 2014). These conditions refer basically to two variables: (1) the degree of governance, state capacity, and institutional strength of the bordering states (strong vs. weak states); and (2) the prevalent socioeconomic situation of the bordering states.
In empirical terms, we focus especially on the Americas (North America, Central America, and South America) since the end of the Cold War, as the continent is characterized by international peace, domestic peace, and regional integration in several of its regions. There is a stark contrast between the realities of interstate peace and domestic peace and phenomena of low-intensity domestic violence, including a high rate of homicides and transnational crime (see Briscoe 2008). In addition, the coexistence of peaceful borders and illicit transnational flows is not unique to the Americas. Similar phenomena can be found in Western Europe (the Schengen Area) and in Southeastern Europe since the conclusion of the Dayton Agreements of 1995; in Southern Africa since the peaceful transition to democracy in South Africa in 1994; and in Southeast Asia since the Paris Agreements that ended the Vietnamese-Cambodian conflict in 1991. Thus we suggest that the phenomenon is transregional and not unique to the American continent, so the conclusions of this article might also be relevant for a more comprehensive understanding of the possible links between peaceful borders and illicit transnational flows.

The Empirical Puzzle and the Theoretical Framework
The puzzle that motivated our research stems from an initial empirical investigation of the tri-border area (TBA) among Argentina, Paraguay, and Brazil. Once these borderlands became peaceful, open, and demilitarized following the 1979 Agreement on Itaipú, which launched the rapprochement between Argentina and Brazil, and the formation of MERCOSUR in 1991, there has been an increased incursion of transnational VNSAs, including transnational criminal organizations and terrorist cells. Thus, the TBA has evolved from including a once-militarized border between Argentina and Brazil to become a border area that is highly integrated in economic and social terms, though it is overwhelmed by smuggling, trafficking, and transnational crime. The TBA's dangerous combination of ungoverned areas (especially in Paraguay) and lack of state capacity (in the case of Paraguay and to some extent Argentina and Brazil), together with poverty, illicit activities, disenfranchised groups, and ill-equipped law enforcement agencies, have resulted in a dangerous enticement and incitement for the proliferation of illicit activities, ranging from criminals to terrorists (see Kacowicz 2015).
We concur with Peter Andreas (2003) that it should not be at all surprising that peaceful borders enable transnational crime and terrorism, although not many researchers have addressed this link in explicit terms or examined it empirically in the Americas, as we do in this article. If the border is closed, it is difficult and risky for transnational actors to cross it. Once the border is open, both legitimate and illegitimate actors can cross it. After all, most illicit business is like licit business; we know that peace is usually good for commerce and trade. The exception might be those specific forms of trade that tend to thrive on armed conflict, such as arms trafficking, embargo bounty, and even stealing humanitarian aid. Conversely, illicit trade uses the same channels and transport mechanisms as licit trade, so it tends to be much more constrained during wartime. Hence criminals and terrorists might benefit and thrive under conditions of peace. Moreover, we have to keep in mind that whereas illegal markets have been territorially bounded and isolated in the past, nowadays they tend to be interrelated and mutually supporting across borders as they are more embedded in the legal global economy and the single market, as promoted by processes of economic globalization (see Giraldo and Trinkunas 2015, 387;and Naím 2005).
Accordingly, illicit actors tend to use and abuse the borderlands; they might prosper when the borders are open and porous. The logical explanation works as follows: paradoxically, it is the essential characteristic of international borders as delimiting lines of international sovereignty and jurisdiction that attracts the incursion of illicit actors. The border provides enticing opportunities for those who can navigate through and around it, including illicit actors, taking advantage of the jurisdictional arbitrage. We should keep in mind that state agents are usually very reluctant to pursue illicit actors into the sovereign territory of neighboring countries, since that is a flagrant violation of international law (for instance, the Colombian attack against a FARC camp across the border in neighboring Ecuador in 2008). Differences between states in their jurisdictional authority, regulatory structures, level of governance, markets, and socioeconomic conditions drive the activity of illicit actors, which, like economic firms, take advantage of this "arbitrage," especially smugglers and other transnational criminal organizations (see Andreas 2003). What should interest us is to explain the variation in the amount of transnational criminal and terrorist activities across the borders. That variation is a function of the conditions under which peaceful borders might allow for the proliferation of illicit transnational flows.
Therefore we posit the following research question: Under which conditions might peaceful borders enable the proliferation of illicit transnational flows, usually perpetrated by nonstate actors, including transnational criminal groups and terrorists? The answer refers to the following variables: (1) The degree of governance and institutional strength of the bordering states, with a special focus on state capacity, border control, and levels of corruption in the borderlands, as a measure for the weakness (or alternatively the strength) of state institutions; (2) The prevalent socioeconomic conditions of the bordering states, with particular reference to the regional economic characteristics of the borderlands, which might provide an economic rationale for or against the incursion and proliferation of transnational criminal activity (and to a lesser extent, of transnational terrorism).

The degree of governance and institutional strength of the bordering states
Governance implies institutionalized modes of social coordination to produce and to implement collectively binding rules, by state and nonstate actors alike (see Risse 2011, 9). The inherent tensions between agents of disorder and governance play themselves geopolitically at the national borders, which are the meeting point and confrontational spaces between the national claims of sovereign governments and the dynamics of globalization and transnationalism embodied by nonstate actors (see Williams 2010, 44). These encounters between the forces of governance and disorder are dynamic and complex; they become even more complicated when we take into consideration three additional factors. First, there is often an asymmetry in the level and forms of governance across the neighboring countries, as a function of different legal systems and levels of economic development, corruption, and institutionalization (or lack thereof) of the rule of law; this is called "jurisdictional arbitrage." Second, the VNSAs that are typically stereotyped as "forces of disorder" might play sometimes positive functions of governance, like policing and providing essential social services, when these functions are neglected or ignored by the relevant state actors that are unable or unwilling to perform them due to their weakness or ineptitude (see Podder 2017). Third, the official actors that embody the government and should therefore provide governance might be corrupted, criminal, and might collaborate with transnational nonstate actors to the extent that it might be difficult at times to differentiate between criminalized state actors and other private, nonstate actors engaged in illicit transnational activities. We have to be aware that at times state strength has nothing whatever to do with a firm determination to prevent the incursion of illicit transnational actors.
Turning to state institutions, we assess different levels of governance by examining the complex relations between states and their societies, usually in terms of "strong" and "weak" states (see Buzan 1983;Migdal 1988;and Holsti 1996). In this sense, the weak state/strong state continuum-measured by state autonomy, degree of legitimacy, and institutionalization-is essential to assess the capabilities and willingness of the state to be physically (and normatively) present at the borderlands. Accordingly, we can formulate our first hypothesis as follows: H1: If both states across the borders are strong, then peaceful borders might not enable the proliferation of illicit transnational actors.
According to this hypothesis, strong states might have an inherent advantage in keeping their peaceful shared borders free from the incursion of nonstate actors due to their internal capacities and legitimate control, low levels of corruption, and high levels of institutionalization.
By contrast, weak states lack capabilities involving the regulation of social relationships and the appropriation of resources in determined ways, and they demonstrate the failure and inability actually to implement decisions, partly due to the weakness in their institutional structure (Migdal 1988, 8, 21-22; see also Centeno 2002, 10). Moreover, weak states fail to fulfill the fundamental functions associated with the effective exercise of sovereign statehood, such as preserving a monopoly over the use of force and providing their citizens and residents with security from physical violence (see Patrick 2011, 8). In this case, the borderlands might function as a no-man's-land or "area of limited statehood" (Risse 2011), or an "ungoverned space" (Clunan and Trinkunas 2010), because of a combination of peaceful and porous borders, criminal activity, and terrorism, with a limited exercise of state sovereignty over external borders. Under these circumstances, nonstate actors might thrive in areas devoid of effective governance, especially in the security realm (see Popescu 2012, 91;and Clunan and Trinkunas 2010). Accordingly, we can formulate our second hypothesis as follows: H2: If at least one of the two bordering states is weak, then peaceful borders might enable the proliferation of illicit transnational flows.
Whereas state fragility and weakness do appear to exacerbate transnational threats, the relevant gaps in national governance across borders might refer to political and security variables such as levels of corruption, rule of law, and differential levels of violence (see Patrick 2011, 246). Thus gaps in governance across neighboring countries might attract and facilitate transnational criminal actors taking advantage of the jurisdictional arbitrage. Poor regulatory structures impede the efficient control of borders against the incursion of illicit transnational flows, including transnational organized crime and terrorist activities. Moreover, high levels of corruption in the police and other law enforcement agencies might hamper anticriminal and counterterrorist efforts. For these reasons, a state's limited control of its national borders becomes an important element in our analysis.
These two hypotheses (H1 and H2) seem to indicate that the nature of the correlation between peaceful borders and the proliferation of illicit transnational flows might depend on the willingness and ability of national governments to control and exercise effective governance in their borderlands and over their borders. We should emphasize that at times there might be an important variance in the level of national governance across different regions within the same country (for instance, obvious gaps between the "strong" core or hinterland and the "weak" periphery of the borderlands). Therefore, the significant independent variable here might be the level of state strength or weakness as evidenced especially in the borderlands, as well as the possible governance gap between the bordering states.

The prevalent socioeconomic conditions of the bordering states
Another explanation for the proliferation of illicit transnational flows across peaceful borders refers to the political economy of the bordering states and their borderlands. There are many instances where states of all sorts of strength might voluntarily absent themselves from establishing border controls (whether physical or virtual, as in the case of offshore financial markets), for purely economic, cost-benefit reasons. Accordingly, international borders have become international political-economic arenas of transactions and economic flows that bring about divisible and mutual benefits (see Simmons 2006, 252;and Kahler 2006).
There are several political economic reasons that explain this nexus between peaceful borders and transnational illicit flows. First, the presence and incursion of malign nonstate actors across the borderlands occur simply because of the economic incentives to take advantage of the jurisdictional arbitrage created by sovereign states in terms of socioeconomic disparities and gaps between the bordering states. In other words, if nonstate actors can find profit in a jurisdiction because it has stricter laws that generate higher prices (for everything from smuggled contraband to illegal drugs), while operating within a jurisdiction with looser or more liberal regulations, then they will seek to exploit it. In this context, cross-border flows are a function not only of supply and demand but also of currency exchange rates and price differentials across the border. Hence, the borderlands become ideal environments for illegal flows of goods that exploit asymmetries and disparities of value (Williams 2010, 44-45).
Second, the poor economic situation in weak and fragile states might create a conducive environment for the proliferation of transnational crime. For instance, weak and poor states sustain high rates of unemployment, especially among youth. That creates an enticing economic opportunity to recruit "personnel" for criminal and terrorist organizations who have no alternative source of income and an uncertain future. It also creates the incentive for legal and illegal migration from poor to richer countries in the region.
Third, economic development gaps across borders might explain not only legal and licit labor and capital flows but also illegal flows through illegal migration and transnational crime in the form of human smuggling and human traffic, as people seek to move across borders regardless of what the border regulatory or security apparatus tells them to do (Payan 2014, 14). Accordingly, we can formulate our third hypothesis as follows: H3: Poor economic conditions and/or disparity in the socioeconomic conditions across the peaceful borders might enable the proliferation of illicit transnational flows involving VNSAs.
Conversely, high levels of economic development might balance out the proliferation of illicit transnational flows, but only if it holds for all the bordering countries in the borderlands. Thus, in addition, we assume that there should not be a significant gap in the socioeconomic conditions of the bordering countries, which should be relatively developed in economic and social terms, so that there will be fewer economic incentives for illicit transnational activities through the borderlands. Still, the economic logic of illicit trade, if supply and demand are located across the border of developed economies, might still trump the logic of the hypothesis. We can then formulate our fourth hypothesis as follows: H4: Sustainable and developed socioeconomic conditions in all of the bordering states, and especially in peaceful borderlands, might disable the proliferation of illicit transnational flows involving VNSAs, if there are not enough economic incentives in terms of supply and demand across the border.
We assume here that peaceful borderlands characterized by high levels of economic development and integration might provide an environment less conducive to the proliferation of illicit transnational flows, even though the borders might become porous, open, and irrelevant. Moreover, we assume that the improved economic conditions across the border might prevail over the logic of supply and demand of illicit flows, if necessary.
To answer the research question and test empirically the four hypotheses presented above, we employed two types of methods. First we collected data regarding the twenty-four countries in the Western Hemisphere that share thirty-six land borders, with reference to the following transnational illicit activities: drug trafficking, human trafficking, arms trafficking, and transborder terrorism. We gathered that information from open sources such as the United Nations Office on Drugs and Crime (UNODC), the US State Department, regional organizations from the Americas, and other Latin American sources in English and Spanish for the years 2010-2015. Additionally, we gathered relevant data about the twenty-four relevant countries in the Americas that share land borders. The data includes: (1) indicators of governance and state strength or weakness, such as the Corruption Perception Index (for 2015) and the Fragile State Index (for 2015); (2) indicators of political economy, level of economic development, and economic gaps between the neighboring countries, such as the Human Development Index (HDI) (for 2014), the KOF Index of Globalisation (2015), and the gross domestic product per capita (for 2014); (3) indicators of political freedom and democracy, with reference to the Freedom House annual report on political rights and civil liberties (2015). Instead of using a quantitative methodology, we prefer to compare dyads.
Second, in addition to the compilation of data for the relevant Western Hemisphere countries, we specifically refer to four case studies to examine the four hypotheses presented above: (1) The North American borders (US-Canada and US-Mexico) since the establishment of NAFTA in 1994; (2) the Northern Triangle of Central America (the borders of Guatemala, Honduras, and El Salvador) since the end of the civil wars in the early 1990s; (3) the Colombian borders (with Venezuela, Ecuador, Peru, and Brazil); and (4) the tri-border area of the Southern Cone of South America, including the peaceful borders among Argentina, Brazil, and Paraguay.

The Reality of Peaceful Borders and Illicit Transnational Flows in the Americas
Since 1881, the relative absence of international wars in the Western Hemisphere has affected its border relations by making them stable and peaceful in terms of the territorial status quo. At the same time, these borders are vulnerable to the proliferation of illicit transnational flows and the incursion of malign nonstate actors (see Kacowicz 1998;and Briscoe 2008). In contrast to cases such as Kashmir, Sudan, Kosovo, and the Arab-Israeli conflict, in the Americas there have been almost no wars since the end of the nineteenth century revolving around the demarcation of national borders (see Briscoe 2008, 1;Jaskoski, Sotomayor, and Trinkunas 2015, 7;and Williams 2016, 268). While this has been a blessing in comparison to the bloody history of Europe until 1945 and much of the contemporary Third World since then, it had also slowed the development of Latin American states by damaging their legitimacy and degree of institutionalization, due to recurrent civil wars and military coups d'état (see Centeno 2002). While international borders are mostly peaceful, and they usually have been recognized as such, they also have been penetrated by the incursion of transnational nonstate actors, including armed criminal networks, transnational criminal organizations, and to a lesser extent, guerrilla and terrorist groups engaged in a myriad of illicit transnational activities and flows (see Domínguez 2018). In sum, Latin American borders, while peaceful in traditional security terms, historically have been neglected peripheral borderlands, and they have gradually become magnets of transnational and domestic violence, with political repercussions and shock waves amplified by the lingering weakness of many Latin American countries (Chinchilla 2011, 2).
To assess the four hypotheses presented above, we assemble two tables that summarize the relevant empirical information concerning illicit transnational flows in the Americas across their thirty-six land border dyads (Table 1), and the ranking of all the relevant countries in the Americas regarding indicators of governance, globalization, political economy, and political regime ( Table 2).
From the information gathered in these two tables, we can now evaluate and test our four hypotheses.

Hypothesis 1: Degree of governance and institutional strength of the bordering states
On the basis of data drawn from the Fragile State Index (2015) and the Corruption Index (2015) recorded in Table 2, we can compile a short list of relatively strong states in the Americas that includes Canada, the United States, Costa Rica, Chile, and Uruguay. In a second category of relatively strong, or functioning, states we might find cases with good rankings in terms of democracy and sustainability but a poor record in terms of corruption, such as Argentina, Brazil, and Panama. Accordingly, the border dyads including these strong and relatively strong (or functioning) countries are far apart. They include the dyads of US-Canada, Panama-Costa Rica, Argentina-Chile, Argentina-Brazil, Argentina-Uruguay, and Uruguay-Brazil.
Turning to the findings summarized in Table 1, we find a significant link between dyads involving strong and functioning states and the relative absence of illicit transnational flows. This is indeed the case with the dyads US-Canada (only low incidence of smuggling and arms trafficking, Argentina-Chile (only smuggling), Argentina-Brazil (with the exception of arms trafficking), Argentina-Uruguay (only smuggling),  . See also Bagley 2008, Briscoe 2008, and Mejías 2014. As in most reports, we include guerrilla acts and all related terrorist activities, such as kidnappings, presence of terrorist bases beyond the borders, and fundraising. We particularly identify the Colombian spillover effects of the FARC on neighboring countries, at least until 2016, as well as the spillover effects of groups such as Shining Path in Peru. We also identify parts of the TBA area, among Argentina, Paraguay, and Brazil, for its suspect transnational terrorist activities.
and Uruguay-Brazil. In this regard, the Costa Rican-Panamanian border might be the exception to the rule, with clear evidence of drug trafficking and human trafficking. Hence, Hypothesis 1 seems to be corroborated in the Americas. As for the particular case studies in the Americas, the hypothesis clearly holds in the case of the US-Canadian border. Both Canada and the United States are strong states within NAFTA. As of 2015 Canada and the United States ranked 9 and 8 in the Human Development Index, whereas Mexico ranked 74. In the Fragile States Index (2015) Canada ranked 10, the United States 20, and Mexico 79. Whereas the US-Mexican border records significant illicit transnational flows, the presence of nefarious nonstate actors along the * KOF Globalisation Index for countries ranges from 1 to 2017 (1 = the most globalized country). ** HDI: Human Development Index ranges from 1 to 188 (1 = the most developed country, in terms of human development). *** GDP: Gross Domestic Product, it ranges from 1 to 185 (1 = the richest country in the world). **** Fragile State Index ranges from 1 to 178. We have reversed the order of the original index, so 1 = the most sustainable country in terms of governance and political development, to fit the comparison with the other indicators in the Table. ***** Corruption Perception Index ranges from 1 to 167 (1 = the least corrupted country in the world). ****** Freedom House's Annual Report: Each country's score is based on two numerical ratings from 1 to 7 regarding political rights and civil liberties; with 1 representing the most free, and 7 the least free.
US-Canadian border remained scant, although we might register some form of illicit transnational flows of illegal migrants (from the US to Canada), unrelated to human smuggling or trafficking. As for the Colombian case, we cannot consider Colombia and several of its neighbors as clear-cut strong states, though there is an interesting variation across the relevant dyads. Brazil and Panama belong to the category of functioning states with good rankings in terms of democracy and sustainability but a poor record in terms of corruption. Thus, the hypothesis does not seem to be relevant in this case.
Turning to the TBA in the Southern Cone, Paraguay fits squarely into the category of a typical (or even stereotypical) weak state, whereas Brazil and Argentina can be considered relatively strong or functioning states with good rankings in terms of democracy and sustainability but a poor record in terms of corruption, which leads Argentina and Brazil not to control their borders properly. The bulk of transnational criminal and terrorist flows have taken place between Paraguay and Brazil (crime) or between Paraguay and Argentina (terrorism), more than directly between Argentina and Brazil. At the same time, the relatively high levels of corruption in Brazil and especially in Argentina create a political environment conducive to the commission of transnational crimes, especially those of the financial type (for instance, tax evasion is the predicate crime in the majority of Argentine money-laundering investigations). Hence the relevance of the hypothesis is somewhat ambiguous and murky: it might partially explain why we find arms trafficking and smuggling across the Argentine-Brazilian border, rather than other types of illicit transnational flows.

Hypothesis 2: Degree of governance and institutional weakness of the bordering states
From the data presented in Table 2, we learn that weak states predominate in most of the Americas, particularly in Central America and the Caribbean. These states include Guatemala, Honduras, El Salvador, Nicaragua, Guyana, Suriname, Paraguay, the Dominican Republic, Haiti, and Belize. In a different category of weak states we find a number of South American countries with high economic potential and rich in natural resources but with high levels of corruption, fragility, and lack of political rights and freedoms. That category includes Colombia, Venezuela, Ecuador, Bolivia, Paraguay, and to a lesser extent Peru. In a special category by itself might be Mexico, which might be a dysfunctional state rather than a weak one. When we assess the data presented in Table 1, we find that all sixteen dyads involving weak states record a number of transnational illicit activities. Therefore, Hypothesis 2 proves relevant for all these cases.
As for the US-Mexican border, whereas we regard the United States as a relatively strong state, Mexico is a relatively weak state, especially in terms of its political corruption. That weakness is reflected in the existing inequality, poverty, and especially the corruption of some of its political institutions, which have undermined the foundations of the state and the enforcement of the rule of law. Popular alienation from the corrupted political class was a key factor in explaining the landslide electoral victory of Andrés Manuel Lόpez Obrador in June 2018. At the same time, we agree with Stewart Patrick that Mexico might be a relatively weak and dysfunctional state but not a completely failed one, so it might sustain some elements of institutional and governance strength. Mexico has been a consolidated democracy since the early 2000s; it does not have major ethnic cleavages or secessionist problems; and some of its institutions are rather robust. This might provide a better incentive and environment for transnational nonstate actors to thrive and prosper in a reality of the inconclusive "drug war" (Patrick 2011, 164).
In the case of the Northern Triangle countries, data drawn from the Fragile State Index, the Corruption Index, and the Freedom House's Annual Report provide clear evidence that they are all weak states. Their institutional weakness and low levels of governance make it difficult for Guatemala, Honduras, and El Salvador to cooperate against their common transnational threats in the form of drug trafficking, human smuggling and trafficking, and arms trafficking (see Domínguez 2018;Carreras 2013;and Bruneau 2014). In many cases, security officials are not only overwhelmed in both numbers and capabilities, but they actually collaborate with those nonstate actors in rural and borderland areas because of high levels of corruption and feeble enforcement of the rule of law.
In the Colombian case, most of the countries that compose the Colombian border dyads belong to a special category of weak South American states that have high economic potential and rich natural resources but also rank very high in terms of corruption, fragility, and lack of political rights and freedoms. The relevant list includes Colombia, Venezuela, Ecuador, and Peru.
As shown in Table 2, the Colombian borders cover an area that we should consider as lacking governance. Colombia and Venezuela are among the most fragile states in Latin America, with scores of 117 and 104, respectively, and are considered in an "alert" situation. They are also highly "corrupted," especially Venezuela and Ecuador, with scores of 158 and 107, and they are increasingly "less free." Moreover, the trends of the last decade show that Venezuela is one of the few countries whose scores changed drastically for the worse, as it is experiencing a tragic process of imploding (see Wajner and Roniger 2019). Hence, this hypothesis is validated in the case of the Colombian borders. The incursion of nonstate actors, initially from Colombia, has spilled over and spread over to neighboring countries in the form of guerrilla and transnational terrorist activity, as well as drug trafficking, human trafficking, and arms traffic. There has been a constant process of weakening of the Colombian state over its borderlands in peripheral areas, and that process had a contagion effect on Colombia's neighbors (see Briscoe 2008, 4).
As for the TBA in the Southern Cone, it is obvious that the responses attributed to the three national governments in the TBA are crucial to explain the dynamics of illicit transnational flows in the region. It is important to consider the historical and political realities and political cultures of Brazil, Argentina, and Paraguay to understand their rather ambiguous positions regarding criminal and terrorist activities in the TBA region. The paradigmatic example is that of Paraguay, a quintessential weak state. In Paraguay, under General Stroessner's thirty-four-year dictatorship, which ended only in 1989, money laundering and counterfeiting were actually encouraged. Furthermore, as mentioned above, all three countries, and not only Paraguay, suffer from high levels of corruption. According to the Corruption Index of 2015, Brazil ranks 76, Argentina 107, and Paraguay 130.
The region has remained largely ungoverned due to the prevalence of weak, inadequate, or ignored laws. The TBA's role in enabling transnational criminals and terrorists has been exacerbated by the inability of the Paraguayan, Brazilian, and Argentine governments to effectively enforce the rule of law in the region and govern in a transparent and decent way, because of widespread corruption. This is particularly evident in the case of money laundering, which allows for other criminal and terrorist activities. In sum, the hypothesis is valid in this case.

Hypothesis 3: Disparity in socioeconomic conditions across the borders
As expected, there seems to be a significant correlation of weak states (in terms of low levels of governance) with poor economic conditions and both socioeconomic and political underdevelopment. Thus we find that all the dyads involving underdeveloped countries (with low rankings of HDI and of GDP) experienced a significant proliferation of illicit transnational flows, including drug trafficking, human smuggling and trafficking, and weapons trafficking. This includes the dyads Dominican Republic-Haiti, Guatemala-Honduras, Guatemala-El Salvador, Salvador-Honduras, Honduras-Nicaragua, Guyana-Suriname, and Bolivia-Paraguay.
Turning to socioeconomic disparities, we also found a positive correlation between asymmetrical socioeconomic conditions across the border and the proliferation of illicit transnational flows, as in the cases of US-Mexico, Mexico-Belize, Mexico-Guatemala, Nicaragua-Costa Rica, Venezuela-Guyana, Suriname-Brazil, Bolivia-Brazil, Paraguay-Brazil, Argentina-Bolivia, and Argentina-Paraguay. In cases of socioeconomic disparities across countries, human trafficking proliferates even more than drug trafficking and arms trafficking. In sum, Hypothesis 3 is corroborated by the evidence summarized in Tables 1 and 2.
As for the particular case of US-Mexican relations, any observer of the border dynamics should be aware of the huge socioeconomic and development gap between the two countries. Whereas the United States is the most highly developed economy in the world, Mexico is still considered a developing economy, despite its middle income (see Payan 2014, 14). This explains why socioeconomic disparity is a key element in explaining the illicit transnational flows between the countries. Different economic environments on either side of the border might create economic incentives for the proliferation of transnational illicit flows, based on a supply-demand relationship (see also Rios Contreras 2014).
Regarding the Northern Triangle countries, one can argue that poor economic conditions in these weak and fragile states create a favorable environment for the proliferation of illicit transnational flows. In a report on the causes of regional migration from the region, Espach and Haering (2012) focused on the socioeconomic conditions in the borderlands of the Northern Triangle countries. Most borderland areas are deprived of basic services including transportation, and they suffer from a general lack of infrastructure. Moreover, the report highlighted the lack of the rule of law along with the almost nonexistent presence of state security forces at the border. Consequently, poorly served and regulated borderlands enable the rise of local VNSAs, who occasionally assume roles of governance and provide services. Among these VNSAs, criminal organizations might compete to fill the vacuum in these ungoverned areas of limited statehood. For instance, in the Guatemalan case, illicit activities, whether domestic or transnational, had a "positive" spillover effect on the communities that benefited and profited from the presence of transnational criminal groups, which provide them with health, security, and education services where the state is explicitly absent. Hence, this hypothesis is very relevant in the Northern Triangle case.
In the case of the Colombian borderlands, it is difficult to discern the relevance of the political economy argument, built on the HDI and GDP data reported in Table 2. In terms of the Human Development Index, Colombia ranks 97, Ecuador 88, Peru 84, Brazil 75, and Venezuela 71. In terms of GDP, Brazil is an overwhelming economic power compared to its neighbors, although its richness is territorially uneven; Amazonia does not seem to contribute substantially to Brazil's national wealth or to attract its neighbors as a magnet for economically motivated migration. Moreover, Colombia and Venezuela were ranked in similar terms (before the most recent implosion of the Venezuelan economy), ahead of Peru, Ecuador, and Panama. Thus we cannot record here striking socioeconomic gaps among the North Andean countries that justify the proliferation of illicit transnational flows.
Conversely, it is probably the socioeconomic gaps existing between the borderlands of Colombia and its political and economic core that potentially permit a political economic rationale for the thriving of parallel, informal, and illicit economies. Moreover, unlike the previous cases discussed in the Americas, Colombia's borderlands have been sites of both production and supply for drug trafficking networks, setting the ideal conditions for the thriving of a great and dense illicit market. For instance, the Colombian-Venezuelan border traditionally has been a focus of smuggling, drug trafficking, oil stealing, and many other networks of extortion. Nowadays it is the dramatic setting for millions of Venezuelans seeking refuge and asylum in Colombia itself.
In the not-so-distant past the borderlands have been a meeting point where the ideological divisions between the FARC and former paramilitaries (some of them turned into Bandas Criminales or BACRIMs), or even the political differences between the two neighboring countries, just disappear due to the vast economic opportunities open for illicit entrepreneurs. As Briscoe (2008, 6) suggests, "within the context of a kind of free market, transnational criminal organizations can buy the rights of transit for drugs from smaller groups, like commercial rights." In sum, we can validate the relevance of this hypothesis for the Colombian borders.
In the case of the TBA in the Southern Cone, the roots of the criminal/terrorist problem in the region follow a clear economic logic. While Brazil is the largest Latin American economy, seventh in the global ranking, Paraguay, at the other extreme, is one of Latin America's most corrupt and poorest countries. Political and economic instability have made Paraguay reluctant to change the reality of criminality in the TBA, since it heavily relies on the informal economy in Ciudad del Este. Huge disparities in incomes and prices among the three economies have contributed to the creation of a smuggler's and money launderer's paradise. In other words, the TBA is a transnational economic space, where the movements of people and goods actually reflect the economic asymmetries among the three countries. Thus this case corroborates the relevance of this hypothesis.

Hypothesis 4: Sustainable and developed socioeconomic conditions across the borders
In Tables 1 and 2, we find a very short list of bordering countries with sustainable and developed socioeconomic conditions. That list includes the cases of US-Canada, Costa Rica-Panama, Argentina-Chile, Argentina-Uruguay, and Uruguay-Brazil. Not surprisingly, these dyads have experienced less illicit transnational flows across their borders. These bordering countries tend to be relatively strong and developed countries, not only in economic terms but also along political and institutional lines. Thus, Hypothesis 4 is validated according to the empirical record summarized above.
In the particular case of US-Canadian relations, the hypothesis is corroborated. The highly developed socioeconomic conditions that reign across the Canadian-US borderlands help us explain the minor or even insignificant presence of transnational criminal groups, in juxtaposition to the socioeconomic gaps across the US-Mexican border. In this case, the economic "push" for transborder illicit transactions along with the licit ones might be balanced out by the "pull" logic represented by the absence of a clear arbitrage if the two economies across the border are similar, in this case rich and developed.
As for the Colombian borders, the hypothesis does not seem very relevant. One might make an exception and refer to the particular case of Colombia-Brazil, as related to the fact that they are the fourth and first Latin American economies. At the same time, even if Brazil is the largest economy of Latin America, Amazonia and the Brazilian North are considered to be the poorest regions in this vast country. Hence the fact that the borderlands between the two countries are located in the Amazonian region partly explain the existence and persistence of transnational illicit flows in the form of drug trafficking and weapons trafficking.
As for the TBA in the Southern Cone, even if we consider Brazil and Argentina as relatively rich and developed economies, this hypothesis is not relevant regarding the TBA in general since it leaves Paraguay out of the equation. As for the Argentine-Brazilian dyad, indeed we traced only arms trafficking across their border, so the hypothesis is partly corroborated.

Conclusions
This article has introduced an analytical framework in an attempt to better explain and understand the coexistence of peaceful, open, and soft borders with illicit transnational flows, as evidenced by drug trafficking, human trafficking and smuggling, weapons trafficking, and terrorism. In any case, the existence of peaceful borders might be neither a necessary nor a sufficient condition for the proliferation of illicit transnational flows. There is much more variance in the incidence of illicit transnational flows across borders than in the existence of international peace as a precondition, which is almost a parameter in many regions of the world, including the Western Hemisphere, Europe, Southern Africa, and Southeast Asia. The empirical test of the four hypotheses in the Americas can teach us about the relevance of other variables such as the level of governance and institutionalization of the neighboring states, as well as political economy indicators and rationale.
In this article we have examined the aftermath of peace, usually in the post-Cold War period or the last thirty years or so, although we still do not have a longue durée perspective. We did not compare the different cases to previous periods of war that also witnessed illicit transnational flows, since our starting point for this research has been a condition of peace. A comparison of transnational illicit flows from previous periods of war to our contemporary time of peace could be an agenda for further research, but it is well beyond the scope of this article.
Assuming that we have not reached yet a stage of "positive peace" (Galtung 1975), we have to be aware of the relevance of human security and new security threats in this age of prevalent international peace, conceived in rather modest terms as the absence of war. People nowadays no longer die from international wars but mostly from civil wars, homicides, and to a lesser extent, from terrorism. True, peace remains a necessary framework. Still, peace is not a sufficient condition to address the unfolding threats that make up our contemporary security landscape-domestically, regionally, and globally. Hence we have to focus our attention and policy goals on strengthening states' governance and changing socioeconomic conditions.
College of Research and Training, Freie Universität Berlin. His articles have been published in the journals International Studies Quarterly, Foreign Policy Analysis, Diplomacy and Statecraft, Regional and Federal Studies, Latin American Research Review, and Journal of International Relations and Development. His main areas of research and teaching are international legitimacy, conflict resolution, regional cooperation, and populist foreign policies, particularly focusing on their interplay in the realms of Middle East and Latin American politics.