One of the few apparent successes in the wreckage that has characterized the US-led policies in Iraq and Syria has been the role of the Kurds. The emergence of what seemed to be a prosperous, democratic Kurdish region in northern Iraq was its principal bright spot. Moreover, the Kurds have proven to be extremely capable fighters. The ability of Kurdish forces, the Peshmerga, to defend territory from ferocious ISIS military assaults, and even inflict significant defeats on the Islamist insurgents, has increased the ranks of Western, especially American, admirers. The Peshmerga’s tenacious resistance, despite having to rely on antiquated military hardware, has stood in stark contrast to the pitiful performance of the well-equipped, US-trained Iraqi army that ignobly fled encounters with ISIS and relinquished control of major urban centers, such as Mosul and Ramadi, with scarcely a fight.

Although the successes of Iraqi Kurdish forces have received the most attention, their Syrian colleagues have been nearly as successful. Their victory over ISIS in the city of Kobani near the Turkish border was only the most prominent of those triumphs. Kurdish units have gained control over significant swaths of territory elsewhere in northern Syria.

The Obama administration has begun to step up direct military assistance to the Peshmerga. This became quite apparent when the United States provided massive air cover to the Kurdish units that recently expelled ISIS from the city of Sinjar in northern Iraq. That victory threatens important ISIS supply lines between territories it controls in Syria and areas it occupies in Iraq.

Kurdistan has acquired a growing roster of advocates in the United States. Indeed, some opinion leaders have urged Washington to downgrade its support of the Baghdad government and place greater reliance on relations with Erbil, the capital of Iraqi Kurdistan. A few outspoken supporters even regard Kurdistan as second only to Israel as a reliable, democratic US ally in the Middle East — a view encouraged by influential Israelis.

A more sober view is needed. The Kurds are indeed capable fighters, and they are vehement opponents of ISIS and other manifestations of Islamic extremism. However, both the Iraqi Kurds and their Syrian counterparts have their own political agendas. And those agendas inevitably cause problems for the Baghdad government and for Turkey, a key member of NATO.

The notion that Iraqi Kurdistan is merely a semi-autonomous region within a united Iraq is little more than a convenient, and increasingly implausible, diplomatic fiction. The reality is that Kurdistan is an independent state in everything but name, with its own military force (the Peshmerga), its own flag, and its own currency. The Kurdistan regional government (KRG) in Erbil increasingly bypasses the central government to strike lucrative deals with foreign corporations, especially to sell oil on the international market — often over Baghdad’s explicit objections.

It was a revealing development when the forces that liberated Sinjar all flew the Kurdish flag. The Iraqi national flag was nowhere to be seen. The same display of Kurdish separatism was evident during the earlier victory of Syrian Kurdish forces in Kobani. The reality is that Kurdish leaders have no enthusiasm for or loyalty to the Iraqi and Syrian states. Despite sometimes intense internal bickering (especially among Syrian Kurds), their overarching goal is the creation of a Greater Kurdistan. That entity would encompass not only the majority Kurdish regions in Iraq and Syria, but a major portion of southeastern Turkey as well.

Turkey is especially nervous about Kurdish military successes. Ankara regards Iraqi Kurdistan as the probable embryo of a Greater Kurdistan that would eventually seek to incorporate Turkey’s own restless Kurdish minority. The KRG’s apparent willingness to provide safe havens to armed insurgents of Turkey’s Kurdistan Workers Party (PKK), which has launched numerous attacks into Turkey, further angers the Turkish government and has led Ankara’s troops to conduct repeated punitive expeditions inside Iraqi Kurdistan.

Turkish leaders appear to be drawing a firm line against further manifestations of Kurdish separatism, especially in Syria President Erdoğan has stated explicitly that his government will not allow the emergence of a de facto independent Kurdish region in northern Syria akin to Iraqi Kurdistan. That is not surprising. Erdoğan and his colleagues fear that Iraqi Kurdistan and Kurdish-controlled areas in Syria would eventually link up to create an extensive, hostile presence along Turkey’s southern border. Moreover, the principal Syrian Kurdish faction, the Democratic Union Party (PYD), and its armed contingent, the People’s Protection Units (YPG), appear to have even closer ties to the Marxist PKK inside Turkey than the KRG. Expanded Kurdish power, therefore, is seen as a dire menace to Turkey’s sovereignty and unity.

If that factor is not enough to induce caution on the part of Western policymakers, recent developments have also cast doubt on the narrative of Iraq Kurdistan as a stable, prosperous, democratic entity. The Erbil government has faced increasing financial woes over the past year, especially with the plunge in global oil prices, which has greatly eroded the KRG’s principal source of revenue. That problem is exacerbated by blatant cronyism and corruption.

As Kurdistan’s economic success story has faded, so too has the region’s reputation as a bastion of democracy. Human Rights Watch slammed the government’s recent behavior, especially that of the dominant political party, the Kurdistan Democratic Party (KDP) headed by Masoud Barzani, who has been the President of the KRG since 2005. Joe Stark, Deputy Middle East Director for Human Rights Watch, is especially caustic. “The KDP claims to be rights–respecting,” he notes, but it “has a history of shutting down critical voices.”

The political trend is not encouraging. Barzani has remained in office despite the expiration of his legal mandate. Worse, his government has engineered a crackdown on the two opposition parties, the Patriotic Union of Kurdistan (PUK) and Goran (“Change”). The culmination occurred in late October when the KDP unilaterally removed four opposition ministers from their government posts and replaced them with KDP loyalists. At the height of the controversy, KDP-controlled security forces even prevented the speaker of the regional parliament from returning to Erbil. Those forces also closed down two television channels, including one controlled by Goran, which had been critical of Barzani. Much to the dismay of Kurdistan’s Western supporters, the KRG increasingly looks like a Putin-style, illiberal democracy riddled with cronyism and corruption.

Although Kurdish forces may be useful military allies against ISIS, Western leaders need to go into any alliance with their eyes wide open. Cooperating with the Kurds entails a number of troubling outcomes that directly contradict other official US and NATO goals. Those objectives include preserving the territorial integrity and sovereignty of Iraq and Syria and not supporting measures that cause problems for a fellow NATO member, Turkey. Western leaders face some difficult and potentially risky choices.