The borderlands of Turkey, Syria, Iraq, and Iran have been a contested terrain since Kurds were rendered stateless during the collapse of the Ottoman Empire. In recent years, rival Kurdish factions have created distinct models of political autonomy in the Kurdistan Region of Iraq and Northeastern Syria, known by Kurds as Başûr and Rojava. Utilizing an original longitudinal dataset of 20,044 armed conflict events in all four countries with Kurdish minorities, we analyze how the Turkish-Kurdish conflict has evolved since 1984, when the Kurdistan Workers Party (PKK) launched its armed struggle against the Turkish state. Engaging the literature on political violence, proxy warfare, and non-state actors, we make three arguments. First, we show how what was once a dyadic civil war concentrated in southeastern Turkey has metastasized into a conflict that now encompasses vast geographical terrain, all ethnic and religious groups indigenous to the borderlands of Iraq and Syria, and an array of state, non-state, and hybrid actors, including the Kurdish-led Syrian Democratic Forces (SDF) whose rank-and-file members are majority Arab. Second, we show that Ankara began to de-prioritize its anti-PKK operations inside Turkey in 2016, in favor of launching large-scale military operations in Syria and Iraq, the two countries where Kurds have gained most autonomy. As a result, hundreds of villages in Iraq have been depopulated, while in Turkish-occupied parts of Syria, Ankara and its proxies engage in Arabization and Turkification policies. Third, the data we present improves our understanding of how Turkey has worked with proxy forces in the Syrian National Army (SNA) to deter Kurdish aspirations for greater political and cultural rights outside its borders. By comparing the 2018 Olive Branch Operation in Efrîn to the 2019 Peace Spring Operation in Ras al-Ayn/Serêkaniyê, we show that coordination increased between the Turkish military and the SNA over time. As Kurds in Iraq and Syria gained more autonomy from their respective central governments in Baghdad and Damascus, Turkey has maneuvered to increase its control over those semi-autonomous regions, while failing to defeat the PKK. Finally, we highlight the need for further research on forms of colonialism indigenous to the Middle East.