In 1990 the Medellín Cartel led by Pablo Escobar kidnapped him to pressure the Colombian government to revert its support of drug lords' extraditions to the United States.

[citation needed] Upon his return, Santos became an advocate of human rights in Colombia, especially those of victims affected by kidnapping after he himself suffered from this practice.

He created a non-governmental organisation called Fundación Pais Libre (Free Country Foundation), with the intentions of advancing awareness and helping the victims and their families.

Since 2008, Santos has spoken as part of the Shared Responsibility campaign to raise public awareness of cocaine production's impacts on Colombia's forest biodiversity, including deforestation and chemical contamination.

[2] Santos served as Ambassador of Colombia to the United States of America in Washington D.C. from September 2018 to 2020.