The peace treaty announced this week between the government of Colombia and the Revolutionary Armed Forces of Colombia, or FARC, marks more than the end of one war. It is a milestone for peace in the Americas and the world.

The 52-year war between the Colombian state and the FARC is the oldest and only armed conflict in the Western Hemisphere, and the last one held over from the Cold War. From Alaska to Tierra del Fuego, war — in the classic sense of a violent conflict over governance or territory fought by at least one national army — has disappeared. Although drug-related gang violence in Latin America continues, the extinguishing of political armed conflicts from an entire hemisphere deserves note.

One has only to look back a few decades to see how momentous a change this is. In Guatemala, El Salvador and Peru, as in Colombia, leftist armed forces battled American-backed governments, with deaths mounting into the hundreds of thousands. In Nicaragua, the conflict was the other way around: American-backed rebels fought to overthrow a leftist government. The United States and the Soviet Union poured in support that kept such wars raging. The “dirty war” in Argentina also flowed from a clash of left and right, in which tens of thousands were killed.

In that era, wars between countries also occurred regularly. During the 1980s, the United States invaded Panama and Grenada to overthrow their governments. In 1982, Britain and Argentina fought a war over the Falkland Islands. Ecuador and Peru skirmished along their contested border, and a simmering dispute between El Salvador and Honduras burst into war in 1969 after the two countries faced off in a series of bitterly contested soccer matches.