Históricamente, las zonas de frontera han sido espacios para el intercambio comercial y el desarrollo sociocultural entre Estados; sin embargo, un incipiente desarrollo institucio­nal, poderes políticos centralizados y el poco interés en la “periferia” regional, han dejado estos lugares como zonas grises y porosas, apro­vechadas por el crimen organizado y distintos grupos ilegales, los cuales se benefician de la ausencia de una autoridad creíble para cimen­tar estructuras dedicadas a la oferta ilegal y, en algunos casos, reemplazar atributos estatales como el control social y la administración de justicia. En la frontera colombo-venezolana, específicamente en el área de Norte de San­tander y Táchira, el último lustro ha visto una reconfiguración de los actores y las rentas ilíci­tas generada principalmente por la mutación y reorganización territorial de las estructuras armadas ilegales que hacen presencia en el te­rritorio colombiano y, en el caso venezolano, por una serie de complejidades económicas y políticas que han fomentado la criminalización de las fuerzas estatales y su vinculación con el monopolio del mercado ilegal.

The internal conflict in Colombia has propelled the development of security sector reform (ssr) programs; however, these programs have been usually linked to the influence of relations between the United States and Colombia in military and foreign policy terms. The main objective of this essay is to understand said interplay from the mid-1990's to the early 2000's, which marked the biggest transformations to the Colombian defense sector in human rights, doctrine, equipment, and human capital. The analysis shows that such influence allowed for the consolidation of an offensive strategy which helped the Colombian government turn the balance of the internal conflict in its favor.

The advancement and modernization of Colombian military apparatus since the late 1990s has been determinant for the current progress of its internal conflict, which nowadays presents a marked reduction of violence due to a political settlement with the Revolutionary Armed Forces of Colombia (FARC), after more than 50 years of hostilities. Defence policy in all this scenario has became crucial for strengthening the Government of Colombia (GOC) in the face of the challenges presented by guerrillas and organized crime, taking it to regain control of territories, enhance its institutional presence, and state's legitimacy and security. But, how has it been possible all this contemporary process of vibrant military evolution of the Colombian Public Force in the late 1990s and the early 2000s? It seems that a mixture of local and foreign variables made achievable both political will and financial resources, to carry out an ambitious transformation of defence apparatus that ended up by curving the internal conflict in GOC's favor. Such scenario propelled a major plan of military aid sponsored by the United States (US), termed as Plan Colombia, in charge of coping with drug trafficking first and with terrorist-insurgent related activities lately. Thus, the aim of this article is analyzing comprehensively the development of the US-GOC military cooperation in the period 1998-2012, as well as the political underpinnings that triggered the inclusion of both counter-narcotic and counterinsurgent goals. This is going to be done by studying two variables: the GOC's strategy of linking FARC's actions with drug trafficking, international terrorism and human rights abuses to change US perceptions in regard to the use of military cooperation (1998)(1999)(2000)(2001)(2002); and the consequences of the Colombian military strengthening in line with US-GOC military cooperation (2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010)(2011)(2012).The first part, "the FARC and the demilitarized zone (1998)(1999)(2000)(2001)(2002): changing US perceptions", helps to comprehend how the political stature of the insurgents was severely damaged given their instrumentalisation of the demilitarized zone (DZ) as operational base for launching illegal actions.