Turkey’s jailed militant leader Abdullah Ocalan called on his Kurdistan Workers Party (PKK) to lay down arms on Thursday, a move that could end its 40-year conflict with Ankara and have far-reaching political and security consequences for the region.

If the PKK’s leadership heeds its founder’s appeal, which is not guaranteed, President Recep Tayyip Erdogan would gain a historic opportunity to pacify and develop southern Turkey, where violence has killed thousands of people and devastated the regional economy.