In the 16th century, after prolonged wars, Kurdish-inhabited areas were split between the Safavid and Ottoman empires. From then until the aftermath of World War I, Kurdish areas (including most of Mesopotamia, eastern Anatolia, and traditionally Kurdish northeastern Syria) were generally under Ottoman rule. After the collapse of the Ottoman Empire, the Allies contrived to split Kurdistan among several countries. However, they were forced to accept Turkey’s conditions in the peace treaty. Turkey was willing to give up much of its empire’s territory in favor of setting new borders for the modern Republic of Turkey, which included parts of Kurdistan, leaving the Kurds without a self-ruled region. Other Kurdish areas were assigned to the new British and French mandated states of Iraq and Syria.
In the 1970s, a group of radical Kurdish nationalist students led by Abdullah Öcalan in Turkey formed the militant group called Partiya Karkeren Kurdistan (PKK). PKK adopted the Marxist political ideology, with the goal of founding a separate independent, Marxist–Leninist state known as Kurdistan. The PKK fought an armed struggle against the Turkish state for cultural and political rights and self-determination for the Kurds in Turkey. PKK tactics were based on ambush, sabotage, riots, protests, and demonstrations against the Turkish government, and it has continued its guerrilla-type militant offensive for over thirty years. Turkey and the International community has listed PKK as a terrorist organization.
The YPG was formed in 2004 as the armed wing of the Kurdish leftist Democratic Union Party. It expanded rapidly in the Syrian Civil War. A sister group, the Women’s Protection Units (YPJ), fights alongside the YPG. The YPG is active in northern and eastern Syria.
In early 2015, the group won a major victory over ISIL (ISIS) at the Siege of Kobanî, where the YPG began to receive air and ground support from the United States and other coalition nations. Since then, the YPG has primarily fought against ISIL (ISIS), as well as on occasion fighting other Syrian rebel groups.
Several western sources have described the YPG as the “most effective” force in fighting ISIL(ISIS) in Syria. A light infantry force, the YPG has limited military equipment and few armored vehicles.
The YPG has been criticized by Turkey for its alleged support for the Kurdistan Workers’ Party (PKK), especially since a rebellion in southern Turkey began in 2015. Turkey has designated the YPG as a terrorist organization, and in 2018 Turkey captured most of the Afrin Canton area in Syria from the YPG.