The following article is an attempt to understand in accordance with realist thinking, the causes of conflict between Colombia and Ecuador during 2006-2009. In this sense, it explores the characteristics and transformations of the armed conflict, as well as the management of the diplomacy and international relations of the Colombian State. In an internal political instability context, the States seek external extraction and validation; in this vein is analyzed the crisis period, which Colombia opted for diplomacy of the “forces pacification” according to the international attitude of fight against terrorist and an old national program which tries overcoming the internal conflict. This stance contrasted with the Ecuadorian government pacifist attitude, allowing the beginning, developing and worsening of the border conflict.