Succeeding governments of Colombia have been fighting against the Revolutionary Armed Forces — abbreviated the FARC — for 50 years. Yesterday in Havana, Cuba, representatives of the government of Colombia and FARC rebel leaders were all dressed in white after reaching stage four of a six-stage peace agreement, scheduled to be completed in the next six months. If it can be finalized, it will mean the end of guerilla warfare that's lasted for 50 years. Adam Isacson studies regional security policy for the Washington Office on Latin America, a human rights organization.