In the aftermath of the 2002–2003 civil war, in which rebels failed to unseat Gbagbo but seized control of the north of the country, Koulibaly was noted as one of the main hard-line FPI figures surrounding Gbagbo who were hostile to the Marcoussis peace accord and despised opposition leader Alassane Ouattara. He was closely associated with Simone Gbagbo, who was Gbagbo's wife as well as President of the FPI Parliamentary Group. Alleged coup plotters led by Ibrahim Coulibaly were said to have conspired to kill Koulibaly along with President Gbagbo and Gbagbo's wife before being thwarted in August 2003.