The Colombian conflict is overwhelming in its complexity and devastating in its impact on the civilian population. Between 1990 and 2000 there were 26,985 civilian murders related to the armed conflict whilst there were only 12,887 fatalities in military operations. The total number of homicides is much higher: 9,087 homicides in 1983 increased to 28,284 in 1993, although this trend has decreased marginally in recent years. In 1995 there were 92 homicides per 100,000 inhabitants, the highest rate in the world.

This situation is reflected in the growing number of municipalities affected by military action, rising from 227 in 1990 to 498 in 2002 whilst the number of actions targeting the civilian population rose from 172 to 436. This increase produced between 1.5 – 2 million displaced persons between 1985 and 2003, composed mostly of female heads of households, children and the elderly. It also produced a change in the public's perception of a conflict once considered distant from everyday reality but now seen as intervening more and more in people’s lives.

In the Colombian conflict the violence does not revolve around a single clearly defined polarity, with a specific core of economic or ethnic conflicts, but is instead related to various dynamics and different historical processes, which are reflected in more fluent identities and produce frequent changes in territorial control.

As a result of this complexity Colombian society has not established a consensus on the nature and origins of the armed conflict. This is one of the obstacles to a negotiated solution. The disagreements support differing explanations of the violence, ranging from those which privilege objective, structural factors such as political exclusion and socio-economic inequality, to those that centre on the motivations and voluntary choices of the individual actors. This disagreement reflects the heterogeneity of Colombian society itself. In order to address these problems, this article attempts to explain the causes of the conflict by relating its recent development to the rationale of its actors in light of a medium and long-term perspective.

Two historical phenomena are fundamental to understanding the conflict. The first is the campesino colonisation of peripheral areas, which throughout Colombian history has served as an escape route from the tensions created by highly concentrated rural land ownership. In contrast to other Latin American countries, Colombia failed to implement agrarian reform to redistribute land ownership. Instead, a constant expulsion of poor campesinos towards areas of unclaimed frontier occurred, where the presence of the central state's regulatory institutions and interaction with the rest of society and the national economy was minimal. Secondly, in political terms this dynamic was reflected in a gradual state-building process, in which the staggered incorporation of territories and populations resulted in an uneven state presence in the regions. Both processes have their roots in the history of the settlement of the country from colonial times to the present day. Since the beginning of the sixteenth century the most isolated and inaccessible territories were settled by marginalised groups (such as poor whites, mestizos, Afro-Colombians and mulatos). In these areas of peripheral colonisation the organisation of social relations was left to individuals and social groups, and the state lacked the monopoly on justice and the legitimate use of force. Even in more integrated territories, the presence of state structures was uneven or part of a dual power structure whereby its control was exercised through local elites. The combination of the colonisation process with this dependency on local powers made the integration of recently settled territories into the rest of the country highly conflictual.

From the end of Spanish rule until the consolidation of present-day Colombia, many of the rural and political structural problems inherited from the Spanish colony deepened. The often violent confrontation between the Liberal and Conservative Parties dominated political life during the nineteenth and the first half of the twentieth century. These partisan confrontations revolved around the extent and pace of economic and social modernisation and the role of the Catholic Church. They also often served as channels for the expression of conflicts of a more social nature, such as struggles over land, rivalries between different regions and population centres, racial conflicts and confrontations between families or groups of families. These conflicts prolonged the dual structure of power: alongside formally modern and democratic political institutions, the traditional parties functioned as two opposed but complementary federations of local and regional clientelist power networks, serving as bridges between the central authorities of the state and the local and regional realities. In areas of peripheral colonisation state presence was only made possible with the concentration of land ownership. This created a degree of social hierarchy which in turn formed the basis of local and regional powers that could be integrated into the national network of the two traditional parties and the state’s institutions. For these reasons the differing degree of consolidation of state institutions led to diverse expressions of violence in different local contexts. There was violence that confronted the direct rule of the state in the more integrated regions, which was very different from the violence in areas where the state's power had to be negotiated through local power structures. There were still further expressions of violence in areas where the traditional mechanisms of social regulation had not yet been consolidated, or where these mechanisms were in crisis: here there was no clear dominant actor but instead a struggle for territorial control.

In the 1930s the Liberal Party launched social, economic and political modernising reforms. These created an atmosphere of polarisation that prepared the way for the explosion of violence of the 1950s that became known as La Violencia. Violent regional clashes between Liberals and Conservatives spread across the entire country following the assassination in 1948 of the presidential aspirant and popular Liberal leader Jorge Eliécer Gaitán. The reaction in Bogotá on 9 April (the famous 'Bogotazo' riots) and in other regions of the country produced a Conservative counter-attack. In response, rural Liberal and Communist groups formed campesino self-defence guerrilla groups which the Conservatives fought with counter-guerrilla units and hired assassins. It is estimated that some 200,000 were killed from 1946 to 1953.

In 1953 General Gustavo Rojas Pinilla took power, Colombia's only period of military rule in the twentieth century. His government tried in vain to pacify the country through an amnesty for the Liberal fighters, but its anti-communist attitude drew it into confrontation with the guerrillas, igniting a new wave of violence. Rojas's attempt to consolidate his power by marginalising the traditional parties prompted them to unite and overthrow him in 1957.

The localised nature of the violence reflected not only the predominance of local power structures but the fragmentation underlying the traditional parties’ networks of power. Clashes between Liberal and Communist guerrillas also contributed to the atomisation of the campesinos, and the violence strengthened the traditional parties as the collective identities derived from membership were all that gave the violence meaning. The need to end the conflict and the military dictatorship led to the pact between the two traditional parties known as the National Front. For 16 years Liberals and Conservatives alternated the Presidency and divided the positions of state power between them. Although the regime contributed to the political stability of the country, the shared monopoly of power prevented both the political expression of new local powers and an effective response to the social problems that arose in the second half of the twentieth century.

The difficulties faced by the political system became evident during the 1970s and 1980s when rapid changes in society made the existing institutional framework obsolete. From the 1970s onwards, Colombia experienced rapid urbanisation, the secularisation of the middle and upper classes, exposure to international thinking, and the significant growth of secondary and university education. At the same time, the traditional party mechanisms for the expression of social tensions in rural communities began to weaken and a divorce between the traditional parties and the trade unions took place. This situation was exacerbated by the limitations of agrarian reform and the criminalisation of social protest, which illustrated the difficulties faced by the bipartisan regime in introducing appropriate reforms. The heterogeneity of the National Front made reform efforts appear too timid to secure middle and working class support and mobilisation, but too excessive for some of the regional and local elites.

In this context revolutionary guerrilla movements appeared in the 1960s, due as much to the persistence of the campesinos' problems as to the increasing radicalisation of university students and the urban middle classes. From this the Cuban-inspired National Liberation Army (ELN) was formed in 1964 by middle class students and intellectuals, trade unionists and former Liberal guerrilla members. In 1967 the Maoist-influenced Popular Liberation Army (EPL) was created as the armed wing of the Leninist Communist Party. The self-defence groups influenced by the Communist Party in peripheral areas of campesino colonisation transformed into the guerrilla group of the Revolutionary Armed Forces of Colombia (FARC) in 1966, after they had been attacked by the Army. In 1972, the more urban 19 April Movement (M-19) was formed in reaction to perceived electoral fraud in 1970. 

The above situation created a growing divorce between society and politics in the 1970s and 1980s. Moreover, attempts to rationalise the state's bureaucracy and control of public spending unintentionally created further tensions between the technocratic and clientelist sectors, and further discredited the corrupt traditional political class. These events led to a serious crisis of political representation that profoundly affected the legitimacy of the state institutions and the means of political mediation in society. The result of this crisis was the constitutional reform of 1991, linked to peace processes with various guerrilla groups. The new Constitution recognised the ethnic, religious, cultural and regional pluralism of the country and tried to correct the most obvious vices of political life. But many of its reforms were frustrated or limited by subsequent legislation and the reality of political culture. The crisis was further complicated because the new Constitution’s decentralising measures and popular election of mayors and governors dislocated the political mechanisms through which the traditional parties mediated between the localities, the regions and the central state, without creating new mechanisms of political cohesion.

Meanwhile, the contours of violence were being transformed as the guerrillas began to expand from the peripheral areas towards richer areas more integrated into national economic and political structures. The guerrillas' increasing use of extortion and kidnapping as a means of finance started to alter society's perception of the conflict. From this stemmed the development of the paramilitary forces and a certain degree of public sympathy for the use of authoritarian solutions.

Furthermore, drug trafficking activities increased from the end of the 1970s. By the 1990s a significant growth in coca production took place because of the decline of plantations in Bolivia and Peru. Illicit crops found ideal conditions in the peripheral areas of colonisation where there was a low level of state presence and a social base in the form of the colonos (campesino settlers). Powerful drug cartels developed, particularly in Medellín and Cali, and launched a war against the state in the 1980s and 1990s. These were eventually defeated in the mid-1990s by the Colombian government with the military support of the United States. However the cartels divided into smaller groups. The US intensified its focus on Colombian drugs during the Clinton administration with the implementation of Plan Colombia from 1999.

The drug-traffickers, who slowly became landowners, contributed to the creation of paramilitary groups. In Puerto Boyacá in 1982 landowners, politicians, military personnel, ranchers, businessmen and a large oil-company formed the group Death to Kidnappers (MAS), in response to guerrilla kidnappings. The phenomenon began to extend across the country, particularly after 1984: other groups appeared such as the Campesino Self-Defence groups of Córdoba and Urabá (ACCU), founded by Carlos and Fidel Castaño, former members of MAS. In 1997, under the leadership of the Carlos Castaño, the United Self-Defence Forces of Colombia (AUC) was formed as an umbrella group for paramilitaries from across the country. At present some of these groups are negotiating their demobilisation with the government of Álvaro Uribe Vélez.

The expansion of illicit crops has also led to the transformation of the relationship between the guerrillas and drug trafficking. Some argue that the violence after 1980 represents a fundamental rupture with previous violence. To begin with the FARC dedicated itself to regulating relations amongst the campesino coca growers and with the drug traffickers, but gradually became more involved in levying tax on the crops, and later controlling the production and trafficking of coca. The income derived from illicit crops increased the FARC’s autonomy, which no longer depended on its integration into the rural communities. This has given greater emphasis to the military dimension of the conflict and increased the FARC's offensive and recruiting capacity.

At the same time, the penetration of drug-trafficking in Colombian society has contributed to widespread corruption and the delegitimisation of the political class. This reached its peak in 1994 when President Samper was accused of receiving money from the Cali cartel during his election campaign. The infiltration of the drug trade further deepened the fragmentation and privatisation of state power and the crisis of legitimacy of the political regime, and led to the blurring of boundaries between political violence and criminal activities such as extortion or bribery. In this context, the conflict ceased to have an exclusively political rationale and instead combined political and military objectives with economic and social goals; individual initiatives with collective actions; and struggles at a national level with conflicts of a regional and local character. Through this the violence has permeated the fabric of Colombian society, becoming the mechanism for the resolution of private and collective conflicts in the absence of the state.

The historical development of the conflict dynamics demonstrates a different logic to the territorial expansion of the armed actors. The differences in the expansion of the guerrillas and the paramilitaries relate to the agrarian problem, the gradual process of state construction and the campesinos’ perception of their unstable integration into national life. The guerrillas develop in peripheral areas of campesino colonisation, expanding towards:

(1) richer areas, more integrated economically into national and international markets, that coexist with marginalised pockets of colonos, and which are regulated by semi-autonomous local and regional powers;

(2) areas undergoing rapid economic expansion, with little state presence, coexisting with groups of colonos who do not have access to the new wealth nor the mediation of social conflicts by a state supplanted by the local social hierarchies;

(3) previously prosperous and integrated campesino areas with a degree of institutional presence and social regulation by local and regional powers, but where there is economic decline, a breakdown in social cohesion and regulation and the diminishing institutional presence of the state. An example is the coffee-producing region, seriously affected by the international coffee price crisis.

In contrast, the paramilitaries appear in areas that are relatively prosperous and integrated with the national and global economy, and where semi-autonomous and partially consolidated local and regional powers exist. Here the local elites find themselves threatened by guerrilla expansion and abandoned by the central state institutions: they perceive the state's modernising and reformist policies undermining their traditional bases of power and interpret the peace negotiations as a betrayal. From these areas they have expanded towards more peripheral areas, with the support of the local powers.

These counter-posed logics of territorial expansion illustrate the confrontation between two contradictory models of rural economic development, as well as the different levels of integration of regions into national politics. In areas of open frontier in the south and east of the country the overlapping of regions controlled by the FARC and areas of illicit coca crop production by campesinos led to a functional alliance between these actors. Paramilitaries thus consider the south of the country the centre stage for the counter-insurgency struggle. In internal frontier areas, in the north and centre of the country, the model of development based on large-scale ranching and commercial agriculture competes with the peasant economy of the colonos.

This opposing territorial expansion of the armed actors, demonstrates the need for a more refined analysis of the geographic dimension of the violence, which does not cover the entire Colombian territory homogenously nor with the same intensity. Instead, the presence of the conflict varies according to the internal dynamics of the region, in terms of its settlement, forms of social cohesion and economic organisation.

Firstly there is a national dynamic that reflects the conflict over geographic corridors that permit access to economic resources, weapons or movement from zones of refuge to zones of conflict. In this manner the conflicts can be distinguished according to areas:

In the north of the country, the AUC has achieved a degree of control although the FARC is attempting to recover influence in this former stronghold, and the ELN tries to defend its presence in the south of Bolívar. In contrast, in the southeast the FARC has traditionally possessed a large military capacity, which is why the area was chosen for the creation of the demilitarised zone for peace talks during the Pastrana government. However, this dominance has been challenged in recent times: since the 1980s the paramilitaries have been consolidating a military bastion there and since 1999 the Colombian Army has recovered a degree of offensive capacity in strategic areas. Perhaps because of these changes, in the southwest a new geographic corridor is being consolidated which corresponds to an axis that starts from the former demilitarised zone and heads towards the Pacific, taking advantage of the campesino colonisation of the region. Furthermore, US pressure for the eradication of illicit crops introduces variations in the regional conflicts. For instance, on the southern frontier with Ecuador a conflict has developed between the FARC and the paramilitary groups over control of the coca-producing department of Putumayo, which has become the focus of the military strategy of Plan Colombia.

Secondly, there is a regional dynamic that corresponds to the confrontation between the guerrillas and the paramilitaries for control of strategic resources such as petrol, bananas or coca.

Thirdly, the local dynamic reflects the conflicts within the sub-regions, localities and sub-localities (i.e. small campesino villages), which in turn often reflect the conflict between the urban centre (more easily controlled by the paramilitaries or the army) and the rural periphery of the small campesino villages, where the guerrillas can act with greater freedom. There are also confrontations between villages of different ideology, different racial origins, economic dynamics and opposing economic interests.

The result of this triple dynamic of conflict and its diffusion within Colombian society is the degradation of the conflict and a profound humanitarian crisis, which is reflected in numerous human rights and International Humanitarian Law violations. Furthermore, the capacity of the different armed actors to operate in enemy territory and the instability of territorial control produce total uncertainty amongst the civilian population. In these areas the state functions as just another actor, interacting in a diffuse manner with the developing powers. The population is left without a fixed system of institutional references and is constantly exposed to reprisals by one armed group or another, none of whom can guarantee permanent control and protection. They therefore resort to the use of terror in order to ensure the loyalty of the civilian population and to deny the adversary support. This situation is exacerbated in a conflict described as a "war through third parties", where opponents do not confront each other directly but instead attack the real or supposed social base of the enemy. For this reason the Colombian conflict has been characterised as a war against the civilian population.