DIYARBAKIR, Turkey — The Kurds in Iraq are suffering from their loss of the lucrative Kirkuk oil fields, which the central government retook by force recently. What some people might not realize is, Turkey also has a lot to lose because of the change.

Since the British first discovered oil in Iraq at Kirkuk in the late 1920s, the struggle for its ownership has never ceased, although the players involved have changed. This lucrative oil source — whose ownership is claimed outright by both Kurds and Arabs, and partially by Turkey — is back in the news.

During the Islamic State (IS) offensive, the Kurdistan Regional Government (KRG) in Iraq recaptured Kirkuk in 2014. For three years, the KRG sold oil from Kirkuk via a pipeline running from there to the Turkish Mediterranean port of Ceyhan. But tension recently mounted in the region when the KRG held an independence referendum in September. In response, the Iraqi army marched on Kirkuk and with the support of the mostly Shiite, Iran-backed Popular Mobilization Units, captured the oil fields.

Turkey was pleased that Kirkuk was once again under Baghdad's control, particularly because of the 600-mile-long Kirkuk-Ceyhan pipeline. This line, with a daily capacity of 150,000 barrels, was being used only sporadically, and the flow halted altogether after the September referendum. After Baghdad took over Kirkuk, Turkey hoped the flow would resume and serve Turkey's economic interests — but it hasn't.