Cooperation for development in Colombia has had an important presence due to the context of the armed and post-conflict conflict. One of the largest cooperators in the national territory, has been the United States, since the 2000s, increased their projects on issues of democratic strengthening, security and rural development. In the context of the post-conflict, the for peace project was implemented in the municipality of Tumaco, which is the largest producer of illicit crops in the country. Despite the implementation of the cocoa project for peace, it can be observed that for 2017, illicit crops in Tumaco increased. In that sense, it is worth asking; What is the impact of the USA cooperation in Tumaco to the substitution of illicit crops? This question will be developed from a critical perspective on cooperation, taking into account the need to know the complexity of regional and political contexts.