Introduction: A Crisis Testing the Limits of an Alliance
The Shusha Declaration, signed on 15 June 2021, elevated relations between Türkiye and Azerbaijan to the level of a formal alliance. The Declaration provided for a mutual military assistance commitment, defence-industrial cooperation and the coordination of foreign policy. The diplomatic chill of October 2026, however, has laid bare the distance that persists between the alliance’s written commitments and its underlying security culture.
Any assessment of the crisis must also take account of an ethical dimension that cannot be overlooked. For many years, Azerbaijan deliberately kept its relationship with Israel at a low profile. Baku opened an embassy in Tel Aviv only in 2023, even though military and energy cooperation between the two had been under way for decades. To what extent can an ally consider it proper to shield from public view a partnership of such strategic weight, while Türkiye finds itself all but face to face with Israel in Syria? The foreign policy coordination envisaged in the Shusha Declaration deserves to be taken at least as seriously as that question.
- How Did the Tension Begin, and Who Set It in Motion?
The ostensible cause of the crisis and its structural drivers should be examined as two distinct layers.
The visible trigger: the headscarf as pretext. Through decisions dated 21 September and 6 October, the authorities in Baku introduced secular dress codes in schools. Although the texts make no mention of the headscarf, reports soon began to emerge of headscarf-wearing pupils being turned away at school gates in practice. In Türkiye, sharp criticism from Chief Presidential Adviser Oktay Saral and a number of ruling-party deputies followed without delay.
Yet the headscarf is far too slight and inconsequential a pretext to justify a crisis of this magnitude between two allies. That a school dress regulation could carry two states bound by the Shusha Declaration all the way to an empty chair at the Organization of Turkic States summit indicates that the real issue lies elsewhere.
Baku’s perception justified, its response disproportionate. Given that the criticism originated at the level of a Chief Presidential Adviser, Baku’s perception of it as interference in its internal affairs is both understandable and justified. No sovereign state would accept having its education policy corrected by the governing apparatus of an ally.
The response, however, was a markedly heavy-handed reaction, one at odds with established diplomatic practice. Baku issued international arrest warrants for certain individuals in Türkiye on grave charges, including incitement to the violent overthrow of the government. On 21 October, it went on to declare 31 Turkish citizens persona non grata, among them a member of parliament and the leader of a political party. Levelling charges of coup advocacy against columnists and social media posts is a response one would expect from an adversary, not from an ally.
Sovereignty and the asymmetry of power. President Aliyev’s address of 3 October sheds light on the psychology of the crisis. Referring to the Karabakh war, he emphasised that in its hour of need his country had relied largely on its own means and had procured everything it required with its own resources. A day earlier, he had stressed that Azerbaijan’s way of life and domestic choices must be respected. Accounts that have long circulated behind the scenes about the conduct of the war, however, paint a different picture: it is said that the operation was directed from within the Azerbaijani General Staff by a Turkish lieutenant general, that a Turkish major general commanded the units in the field, and that Turkish special forces cleared the way for the advance of Azerbaijani troops. Aliyev’s rhetoric, together with his absence from the Organization of Turkic States Summit in Ankara on 30 October, suggests that the crisis is less a one-sided offensive than a reciprocal test of sovereignty. Baku is seeking recognition as an equal actor, while Ankara wishes to preserve its weight within the alliance. - The Deeper Fault Line: The Israel Factor
The most critical dimension of the crisis lies in the diametrically opposed foreign policy outlooks of the two countries towards Israel.
Ankara’s position. Türkiye has adopted a firm line towards Israel in response to the war in Gaza. According to official figures, bilateral trade between the two countries has stood at zero since June 2024. In Syria, meanwhile, Ankara and Tel Aviv are engaged in a contest for influence that carries the risk of direct confrontation.
The Baku–Tel Aviv partnership. For Azerbaijan, Israel is a critical security partner that supplied the unmanned aerial vehicles and air defence systems instrumental in the recovery of Karabakh. On the energy front, the bond is stronger still: in 2025, approximately 46 per cent of Israel’s crude oil imports came from Azerbaijan, the bulk of it transported across Turkish territory via the Baku–Tbilisi–Ceyhan pipeline before reaching Israeli ports. The visit of Israeli President Herzog to Baku in October 2026, and Turkish Foreign Minister Fidan’s departure from the hall during Herzog’s address, brought this divergence fully into public view.
The picture Aliyev must recognise. Seen from Ankara, Israel’s regional policy, extending from the Eastern Mediterranean to Syria, is increasingly evolving into an agenda aimed at encircling Türkiye. Azerbaijan’s involvement, whether by design or otherwise, in the energy and logistical dimensions of that agenda is exceedingly difficult for Türkiye to accept. The Shusha Declaration did not anticipate a deepening partnership between one of the parties and a third actor that threatens the security of the other. To sustain, without transparency, a relationship that contributes to the encirclement of one’s own ally is a position difficult to defend on ethical grounds. - Where Might the Parties Take the Tension?
Two principal scenarios emerge regarding the future of the relationship.
Controlled cooling and diplomatic rebalancing (high probability). The bridges between the two leaders remain intact. President Erdoğan telephoned President Aliyev on 21 October to invite him to the summit; although Aliyev did not attend, Azerbaijan took part through Foreign Minister Bayramov and signed the 163-article Ankara Declaration. Mutual dependence in the defence and energy fields likewise militates against a rupture. The relationship is expected to evolve away from the rhetoric of “brotherhood” towards a more rational, measured and pragmatic strategic partnership.
Divergence on international platforms (low probability). Matters are not expected to reach this point, though the possibility merits noting. Under this scenario, Azerbaijan could slow Türkiye’s normalisation steps with Armenia, much as it effectively halted the protocol process in 2009. Alternatively, it could cultivate alternative relationships with Russia or with Gulf actors such as the United Arab Emirates in order to counterbalance Türkiye’s regional sphere of influence. - Could the Baku–Tbilisi–Ceyhan Pipeline Be Shut Down?
In terms of economic and geopolitical rationality, the closure of the BTC pipeline is all but inconceivable.
Mutual economic self-harm. The BTC pipeline is the lifeline of the Azerbaijani economy, ensuring the uninterrupted flow of its oil to world markets. For Türkiye, it is both a source of transit revenue and a cornerstone of its strategy to become an energy hub. Whichever party were to close the pipeline would inflict harm on itself before its counterpart.
International consortium and legal commitments. The pipeline is not at the sole disposal of the two countries. It is protected by the investments of international energy companies led by BP and by intergovernmental agreements. A politically motivated closure would entail vast compensation liabilities and a lasting loss of credibility in global energy markets.
Analytical note. The existence of the BTC pipeline also places Türkiye in a delicate position on the Israel question: although Ankara has severed trade with Israel, it maintains that it does not control the final destination of Azerbaijani oil loaded at Ceyhan. However far political tensions may escalate, energy geopolitics will continue to remain a pragmatic domain of high politics.
Conclusion: The Triumph of Pragmatism over Sentiment
Rational state interests will, in the final analysis, prevail over emotional and ideological rhetoric. The crisis between Türkiye and Azerbaijan does not signify the end of the relationship; rather, it marks the onset of a new phase in which Azerbaijan seeks to be recognised as a mature actor exercising full independence in both its domestic and foreign policy.
The sound functioning of this new phase, however, rests on two conditions. The first is that secondary issues such as the headscarf must not be turned into instruments of escalation; such a course is ethically untenable, whether on the part of critics in Ankara or in the form of Baku’s disproportionate sanctions. The second is that an alliance demands transparency. If Azerbaijan wishes to be respected as an equal sovereign partner, it must also place its relationship with Israel, which bears directly on Türkiye’s security, openly on the table, in the spirit of coordination envisaged by the Shusha Declaration. Even as the rhetoric of brotherhood fades, a strategic partnership founded on candour will prove the more enduring.