TOPSHOT - Colombia's President Juan Manuel Santos (L) and Timoleon Jimenez, aka 'Timochenko' (R), head of the FARC leftist guerrilla, shake hands accompanied by Cuban President Raul Castro (C) during the signing of the peace agreement in Havana on June 23, 2016. Colombia's government and the FARC guerrilla force signed a definitive ceasefire Thursday, taking one of the last crucial steps toward ending Latin America's longest civil war. / AFP / ADALBERTO ROQUE (Photo credit should read ADALBERTO ROQUE/AFP/Getty Images)

TOPSHOT - Colombia's President Juan Manuel Santos (L) and Timoleon Jimenez, aka 'Timochenko' (R), head of the FARC leftist guerrilla, shake hands accompanied by Cuban President Raul Castro (C) during the signing of the peace agreement in Havana on June 23, 2016.
Colombia's government and the FARC guerrilla force signed a definitive ceasefire Thursday, taking one of the last crucial steps toward ending Latin America's longest civil war. / AFP / ADALBERTO ROQUE        (Photo credit should read ADALBERTO ROQUE/AFP/Getty Images)