The scandal ensnaring Gustavo Petro's administration revolves around a massive money laundering operation, bribes to politicians, and inflated government contracts.
The principal crossing point from Venezuela into Colombia, the frontier city of Cúcuta, has seen rising levels of violence as it struggles to confront the growing strength of Venezuelan criminal groups.
It is an election year in Venezuela, and President Nicolás Maduro is determined to cling to power. His criminal alliances will be crucial for the survival of his regime.