A ceremony in northern Iraq on Friday saw a handful of Kurdistan Workers’ Party (PKK) militants lay down their weapons, a small but hugely symbolic gesture that marks the beginning of an end to a conflict with the Turkish state that’s lasted nearly five decades and cost tens of thousands of lives.

The disarmament of the P.K.K., a group that has battled since the 1980s for Kurdish independence, could end a conflict that has killed more than 40,000 people.