After a half-century of combat that spilled blood across this South American nation, Colombians have embarked on a new, but difficult path to settle their political differences with the signing of a historic peace accord between the government and leftist rebels.

The first test after Monday’s signing is a weekend referendum in which voters are being asked to ratify or reject the deal. If it passes, as expected, Colombia will move on to the thornier and still uncertain task of reconciliation.