Turkey’s President Recep Tayyip Erdogan never misses an opportunity to swipe at the United States for its cooperation with the Syrian Kurdish militia, the YPG (People’s Protection Units), a key U.S. ally in the fight against ISIL. On an almost daily basis, he slams Washington for “giving weapons to a terror organization” and declares U.S. policy to be a violation of the NATO treaty. When Brett McGurk, the U.S. official responsible for coordinating the international coalition against ISIL, visited YPG members in the Syrian town of Kobane and posed for the cameras with Kurdish commanders, Erdogan asked the United States to “choose between us or the terrorists.” The Turkish foreign minister said he should be sent home while pro-government columnists called for his detention.

But when it comes to Russian support for the YPG, Ankara is mute. Neither Erdogan nor other top ruling party officials uttered a word when the Russian commander at the Hmeimim military base and the YPG spokesman appeared before cameras and made a joint press statement. The Russian commander said they were conducting a joint operation against ISIL in the eastern city of Deir ez-Zor. Russian warplanes provided air cover for the YPG while the Kurdish forces protected Russian forces on the eastern side of the Euphrates.

Turkey’s muted response to Russia’s collaboration with the YPG points to an inconvenient truth for the ruling AKP: Ankara has historically been vulnerable to Russia’s Kurdish policy. In the past, it had leverage to keep Moscow in check. But today, Ankara’s hands are tied. Turkey has no leverage to steer Russia away from cooperating with its archenemy. Ankara might hope Moscow will drop the Kurds as the campaign against ISIL begins to draw to a close. But Russo-Kurdish partnership has deep roots that stretch back to the turn of the last century and might last longer than Turkey would like. As American power in the region is perceptibly in retreat, Russia is trying to fill the vacuum. In Moscow’s regional calculations, the Kurds might prove to be more than great fighters. They could provide the Kremlin with further leverage.

Russia’s Deep-Rooted Relations with the Kurds

The Kurds have historically played an important role in Russian efforts to exert its influence in the Middle East. During the Cold War, the Soviet Union used the Kurds to bypass America’s containment strategy in the region.

Shortly after World War II, Moscow supported the creation of the Kurdish Republic of Mahabad in Iranian Kurdistan to increase its influence in the region. After the Iranian army crushed the Kurdish forces, the fighters led by Mustafa Barzani took refuge in the Soviet Union.

In Iraq, Moscow used the Kurds as a trump card not just against Washington but also against Baghdad. The Soviets supported Kurdish demands for national autonomy. Throughout the 1950s, when Moscow had an opponent in Baghdad, this support became a lever to keep the central government in check. But even in the case of pro-Soviet governments that followed the 1958 revolution, Moscow wanted to preserve the Kurdish trump card. In the 1960s, Moscow led international efforts at the United Nations charging Iraq with conducting a genocidal war against the Kurds. In 1970, Moscow mediated between Baghdad and the Kurds to sign a peace agreement that provided for the autonomy of Iraqi Kurds. After 1973 when the Kurds adopted an openly pro-Western stance due to growing ties between the Iraqi and Soviet governments, the Soviets supported Baghdad’s war against the Kurds, which generated demand for Soviet weapons. No matter which direction they leaned, the Kurds served as Moscow’s leverage in Baghdad.

During this period, the Soviet Union established close relations with Turkey’s Kurds as well. In the 1970s, the Kurdistan Workers’ Party (PKK) was established as a Marxist-Leninist and Kurdish nationalist organization. The works of Vladimir Lenin and Joseph Stalin became the “main, if not the only, ideological sources of the PKK’s assumptions, beliefs, and values.” After the extensive repression that followed the 1980 military coup in Turkey, many PKK members left the country for Syria, a close Soviet ally, where they received considerable support from the Hafez al-Assad regime. Moscow provided material support and training through their proxies but the political support to the PKK was public.

After the Cold War, Russia kept the Kurds as a trump card to exert pressure on Turkey. In an effort to close its widening foreign trade gap and fill the void left by the collapse of the Soviet Union, Turkey sought to cultivate closer ties to the new republics in Russia’s backyard. To restrain Turkey’s influence, Moscow played the Kurdish card.

The 1990s were marked by the height of Turkey’s war against the PKK that had been waging an insurgency against the Turkish state since the 1980s. To exert pressure on Turkey, in the mid-1990s, Russia entertained the possibility of establishing a Kurdish parliament-in-exile in Moscow. In 1995 and 1996, Moscow held several international conferences featuring organizations close the PKK. Turkish media even circulated reports that the PKK set up a camp in Moscow where the militants were receiving military training.

Turkey responded in kind. During those years, Russia was waging its own fierce war against Chechnya. In the early 1990s, after the fall of the Soviet Union, separatists in the newly formed Russian Federation Republic of Chechnya launched a coordinated campaign for independence, which led to two bloody wars. Russia opposed Chechen independence, arguing Chechnya was part of Russia.

Chechens enjoyed strong support in Turkey. During the first Chechen war that started in 1994, Turkey hosted exiled Chechen warlords. Turkish mayors who were members of the Islamist Welfare Party provided medical aid for the Chechen guerrillas. There even emerged calls within Turkey’s Islamist and nationalist circles for a military intervention in Chechnya to support their war of independence. Both Turkish media and Russian officials argued that Turkey was channeling financial and military aid to Chechnya through Turkey-based Chechen organizations. The most notable was the Chechen-Caucasus Solidarity Association, which was reported to have some 10,000 members in Turkey. Russian officials repeatedly asked the Turkish government to close down these organizations and stop sending volunteers and weapons to the Chechens.

This culminated in a protocol agreement to “prevent terrorism” in 1995. Russia agreed not to allow the PKK to set up organizations in Russia. In return, Turkey promised that it would not support the Chechen cause. Despite the agreement, the distrust remained in bilateral ties.

Moscow and Ankara decided to open a new chapter in bilateral ties at the turn of the century. In 2005, Erdogan and Russian President Vladimir Putin met in the Russian Black Sea resort of Sochi and reached an agreement to support each other’s positions on Chechnya and the Kurds. For a while, frictions over the Kurdish issue seemed to be dissipating.

Syrian Conflict Reignites the Kurdish Question

After the Syrian conflict started, however, the Kurdish issue flared up again in Turkey’s relations with Russia. After Turkey shot down a Russian military jet for violating its airspace, Moscow delivered weapons to the YPG in western Syria. In February 2016, a Syrian Kurdish diplomatic mission opened in Moscow. In March 2017, reports surfaced that Russia was building a military facility in Kurdish-controlled Afrin, where Russian military advisors were to provide training to Kurdish forces. The move raised eyebrows in Ankara.

Russia has also provided diplomatic support to the Syrian Kurds. To Turkey’s dismay, Russia proposed a draft constitution earlier this year, which included Kurdish autonomy. More recently, Moscow decided to invite the Democratic Union Party — the political arm of the YPG — to a congress of Syrian ethnic groups in Sochi, and announced the party would be included in the Astana talks. These decisions have become thorns in bilateral relations. Despite Turkey’s objections, Russian officials continue to argue that the Democratic Union Party must be at the table when discussing the future of Syria.

To Moscow, cooperation with the YPG maintains political pressure on Turkey and supports an effective fighting force against the Islamic State, which is a key security concern for Russia. But as in the past, the Kurds of the region serve a larger purpose for Russia’s regional policy. They provide Moscow with a channel of influence in the Middle East.

To that end, Russia has been cozying up to the Iraqi Kurds as well. While Washington, European countries, Turkey, and Iran opposed a move by Iraq’s Kurds to hold an independence referendum in September, Moscow issued no such call to cancel the vote. Instead, Russia announced its latest energy investment in Iraqi Kurdistan and became the lead funder of Kurdish energy deals. The move not only provides Russia with leverage in Iraqi politics but could also establish Moscow in a market that Turkey has been seeking to exploit to reduce its energy dependence on Russia.

Given Russia’s interest in returning in force to the region, Moscow is likely to deepen its ties to the Kurds. In Ankara, that prospect calls up memories of the 1990s. Like in those years, the Kurdish question is Turkey’s Achilles heel. But unlike then, Ankara has no leverage to moderate Russia’s actions. With a pro-Russia Chechen leader in charge, Russia is not as vulnerable to the Chechen nationalist movement, denying Turkey the lever of influence it enjoyed before.

That leaves Turkey weak vis-à-vis Russia. The only way out is for Ankara to return to the peace negotiations with its own Kurds. But that is a dim prospect before the 2019 presidential elections. Erdogan is playing on the Turkish nationalists, rendering a return to negotiations with the Kurds politically risky for the Turkish president. Until Turkey resolves its Kurdish question, Ankara will remain silent on Russia’s cozying up to the Kurds while bashing Washington for doing the same.