Colombia struck a peace deal with guerrilla groups years ago. So why is violence surging?

This year kicked off with a violent start on the Colombia-Venezuela border, where dissident militant factions have been competing for territorial control of lucrative drug routes that connect the South American country to the US and Europe. At least 23 people were killed in violent clashes at the start of the year, followed by a deadly car bomb and the murder of a local community leader and his wife.