Through the first few decades of its existence, the FARC was one of several leftist guerrilla groups fighting the government and Colombian elites. But by the 1990s the FARC had become deeply involved in the drug trade, using the profits to finance a stunning military expansion.
By then, Colombian elites were bankrolling right-wing paramilitary fighters to battle the insurgents. They became the FARC's biggest rivals in the cocaine trade, too. Civilian populations in rural areas where the drug trade thrived were subject to some of the war's worst atrocities.
Military setbacks and the deaths of top FARC leaders — with help from the U.S. government through Plan Colombia — eventually helped force the rebels to the bargaining table and produced the deal announced Wednesday.
The cost of Colombia's civil war is incalculable, but here are some key numbers that help illustrate the conflict — and the forces that have kept it going all these years.
Dead and displaced: the fighting in Colombia has killed more than 220,000 over the past five decades, according to government tallies. Nearly 7 million Colombians have been driven from their homes — the highest number of what the United Nations considers "internally displaced people" (IDPs) in the world. And Colombians will continue to be maimed long after the war ends by land mines, which have killed or injured more than 11,000 people since 1990. That is second-highest number of land mines in the world after Afghanistan.
Rebels in arms: Flush with cocaine profits, by the late 1990s the FARC was at its peak, with nearly 20,000 fighters. It terrorized Colombians with kidnappings, bombings and brazen attacks that came to represent a major threat to the government, controlling as much as one-quarter of Colombian territory. But the FARC's tactics and its criminal reputation earned it little support among the ordinary Colombians on whose behalf it was supposedly fighting. As the state fought back and FARC soldiers grew fearful of increasingly effective military airstrikes, the rebel ranks thinned, with many defecting or deserting. Today the FARC has fewer than 7,000 troops, according to Colombian military intelligence.
Lost opportunity: In the past decade, Colombia has had one of the fastest-growing economies in Latin America. But many Colombian economists and business leaders think the country would be far more prosperous — and perhaps more equitable — if the government wasn't wasting so much of its resources on war. A major component of the peace agreement is a plan to invest heavily in long-neglected rural areas where guerrilla violence has been an obstacle to economic development and the presence of government health, education and social programs. Implementing the peace deal will be expensive — costing more than $40 billion by some estimates — but Colombian officials expect a wave of new investment and development projects that will more than pay for it.
American aid: Over the past 15 years, Congress has sent about $10 billion to Bogota through Plan Colombia, a program of military and diplomatic support aimed at fighting drug cartels and insurgents. The once-controversial program is viewed as a major foreign policy success, enjoying broad U.S. bipartisan support. With the peace deal at hand, President Obama wants to relaunch it as "Paz Colombia," and funding in 2017 will increase from about $300 million to $500 million. Some of the money will go to programs to remove land mines, or promote new crops in neglected rural areas where farmers have long relied on illegal crops such as coca.
Cocaine: Colombia was the world's largest grower during the 1990s and early 2000s, but a combination of tougher enforcement, increased aerial spraying and other tactics cut output by 75 percent. For a time Colombia became the world's No. 2 producer, after Peru. But it was not to last. In the past two years, as the FARC and the government negotiated their deal, the size of the country's illegal coca crop has doubled, and Colombia harvests more than Peru and third-place Bolivia combined.