Ends, ways and means for Riyadh’s two-layer external guarantee after the September 2026 Houthi escalation, with implications for Ankara
ABSTRACT
Between November 2025 and August 2026 Saudi Arabia built two external guarantees: the Strategic Defense Agreement with the United States and, according to Al Jazeera’s reporting, the Mecca Joint Defence Agreement with Türkiye and Pakistan. This piece examines what military help the two layers produced during the Houthi attacks of 8–25 September 2026 and derives an alliance strategy for Riyadh from the result. Comparing reported treaty terms with September statements and actions, it finds that both layers produced declarations and coordination meetings but no deployments, while the concrete hardware came from France, outside both frameworks. It argues that Riyadh should treat the Mecca framework as a signalling and coordination platform, buy defence capacity bilaterally and keep the Iran channel open, and it sets out the costs for Ankara.
1. Where the advantage sits
An alliance commitment is defined here as a state’s written or verbal undertaking to provide military help if a partner is attacked; its credibility is the probability that the help arrives in a crisis. Deterrence means raising an attacker’s expected cost until it refrains from attacking. Lupovici (2010) argued that deterrence theory needs a new research agenda for non-state actors and asymmetric threats, and the Houthis are such an actor. Jervis (1978) defines the security dilemma as the situation in which measures a state takes to increase its own security reduce the security of others and provoke counter-measures. Tang (2009) shows that the concept applies only where parties are uncertain of each other’s intentions and defensive measures can be read as offensive. Houthi attacks are open acts of aggression, so the Riyadh–Houthi relationship is not a security dilemma. The concept matters for how Iran reads a new alliance.
The two Saudi guarantees show an inverse relation between the capacity of the guarantor and the bindingness of the guarantee. On 18 November 2025 the United States designated Saudi Arabia a major non-NATO ally, the two states signed the Strategic Defense Agreement, the F-35 sale was confirmed and the Crown Prince raised his US investment pledge from $600 billion to $1 trillion (Abdalla, 2025). According to ABC News the agreement is an executive agreement, not a treaty requiring Senate approval, and the package includes the sale of 300 US tanks (Martinez, 2025). The US commitment therefore comes from the main supplier of Saudi air defence but rests on the executive’s interpretation. The Mecca agreement, by Al Jazeera’s account signed in Mecca on 7 August 2026 by Mohammed bin Salman, President Erdoğan and Prime Minister Shehbaz Sharif, treats an attack on one member as an attack on all (Al Jazeera, 2026b; Magee, 2026); its official text has not been verified. Its collective-defence wording is stronger, yet the sources reviewed contain no evidence that Türkiye or Pakistan could replace the United States as an interceptor supplier.
2. Saudi Arabia’s position
The September test separated words from deeds in both layers. According to the Houthis’ own statement they launched dozens of missiles and drones at Saudi targets on 24 September; Saudi authorities issued emergency alerts for Mecca, Jeddah and Yanbu and said they had intercepted six ballistic missiles (Reuters, 2026b). Officials told AP that the Kingdom’s interceptor stocks were running low and that Riyadh had asked France, the United Kingdom, Pakistan and Egypt for air defence support; AP linked the shortage to the depletion of US stocks during six months of war with Iran (Magdy et al., 2026).
On the US side, Secretary of State Marco Rubio said on 23 September that Washington had a very strong defence agreement with Saudi Arabia and would honour its commitments under it (Arab News, 2026). Semafor reported the same week that the Trump administration had not provided military aid (Gonzalez, 2026), and AP reported US officials’ reluctance to intervene (The Associated Press, 2026b). The limit of the US guarantee thus reflects competition for interceptors more than an absence of will, and the executive-agreement form let Washington prioritise its own campaign without a dispute over breach.
The Mecca layer followed the same pattern. As of 16 September Türkiye and Pakistan had not committed military support (The Associated Press, 2026b). On 18–19 September Foreign Minister Hakan Fidan said meeting Saudi Arabia’s military needs would pose no problem, and Pakistan’s army spokesman Lieutenant General Ahmed Sharif Chaudhry said Pakistan would defend the Kingdom by every means (Al Jazeera, 2026b). The three foreign ministers met within the agreement’s framework on 24 September (Reuters, 2026b), and on 25 September Turkish and Pakistani defence officials discussed intelligence cooperation and military coordination in Riyadh (Holland & Hafezi, 2026). On 25 September Al Jazeera reported that the mutual-defence clause had not been formally invoked, and Semafor that neither state had committed troops (Al Jazeera, 2026a; Gonzalez, 2026). France, outside both frameworks, sent troops, radar and defence systems to the Yanbu oil terminal on 25 September (Al Jazeera, 2026a). Houthi attacks continued and intensified through September after the early-August announcement of the Mecca agreement; the sequence gives no sign that the agreement changed the Houthis’ cost calculation.
3. Step one: Buy defence capacity bilaterally
The end is air defence that holds under sustained attack. In September hardware arrived through a bilateral supplier, not through either alliance text. Riyadh’s first step is to convert its requests to France, the United Kingdom, Pakistan and Egypt into standing bilateral supply and deployment arrangements. The trade-off is cost and integration: several suppliers mean several systems to connect. The indicator is the number of foreign air defence units deployed at Saudi energy sites.
4. Step two: Give the Mecca framework operational content short of invocation
The Mecca framework’s measurable output in September was coordination: a foreign ministers’ meeting and a defence officials’ meeting on intelligence and coordination. Its next step is a joint air defence plan and an intelligence-sharing procedure that operate without formal invocation of the mutual-defence clause. The indicator is the outcome of the chiefs of staff meeting agreed on 25 September (Al Jazeera, 2026a): a deployment, joint air defence plan or interceptor supply would mark the move from coordination to implementation.
5. Step three: Keep the Iran channel open
Pakistani Foreign Minister Ishaq Dar described the agreement as “purely defensive” and open to other states (The Associated Press, 2026a). In Tang’s terms, an explicit declaration of defensive intent lowers the chance that Iran reads the alliance as an offensive bloc. Pakistan’s army chief Asim Munir discussed the Houthi attacks and the resumption of US–Iran talks with Iranian Foreign Minister Abbas Araghchi by telephone on 10 September (Reuters, 2026a), in the same week as the 8 September attacks. Riyadh benefits from a partner that speaks to Tehran, because an Iran that does not feel encircled has less reason to escalate through proxies. The indicator is continued Pakistani–Iranian contact at army-chief or ministerial level.
6. Step four: Re-price the US guarantee
The executive agreement lets Washington set priorities case by case. Riyadh holds leverage in its $1 trillion investment pledge and its arms purchases, including the F-35 and 300 tanks. The fourth step ties the timing of those purchases to interceptor deliveries, at the cost of friction with an administration that rejected Iran’s 25 September proposal, made through Qatari mediation, to reopen Hormuz and halt the regional conflict within seven days (Holland & Hafezi, 2026). The indicator is any US interceptor transfer to Saudi Arabia.
7. The principal risk
The defensive design carries a price in deterrence. An alliance that declares it has no offensive intent cannot issue a credible punishment threat against a non-state actor that has already attacked. Lupovici’s non-state actor problem appears here: the Mecca agreement offers inter-state reassurance but leaves undefined what happens to the Houthis. The principal risk is that Riyadh, short of interceptors, requests formal invocation and its partners decline, which would expose the gap between text and practice and reduce the framework’s signalling value.
8. Outlook: Türkiye, Saudi Arabia and the World
The first October indicator is the chiefs of staff meeting; its result was unknown at the time of writing. If it produces deployments, a joint air defence plan or interceptor supply, the Mecca framework moves to implementation; if not, the September pattern continues.
For Saudi Arabia, the variable that runs into 2027 is US interceptor consumption in the Iran campaign. If the stock pressure reported by AP persists, Riyadh can be expected to rely on bilateral hardware arrangements such as the French deployment, with the Mecca framework as a coordination platform. Progress in US–Iran talks would ease the constraint; Trump’s rejection of the 25 September proposal gives no sign of that path opening.
For Türkiye, the agreement has been kept at a level that makes political closeness to Riyadh visible without endangering relations with Iran. If invocation is requested, Ankara will face an explicit choice between deploying troops and preserving its Iran policy. Fidan’s wording on meeting military needs currently defines a support space that excludes deployment.
Globally, September 2026 showed that the US guarantee in the Gulf is limited by Washington’s concurrent war burden more than by the written text. If that condition persists in 2027, Gulf states may multiply their security partners, and Dar’s statement that the agreement is open to others leaves an institutional route for enlargement.
9. Conclusion
Saudi Arabia’s two guarantees produced statements and no military aid during the September 2026 Houthi escalation. The US limit came from a low-binding executive agreement combined with Washington’s own interceptor needs. The Mecca agreement did not fill the gap; it gave Riyadh signal value and bargaining leverage and, through its defensive and open design, eased the security dilemma with Iran at the cost of deterrence against the Houthis. The capacity added in September came from France, outside both frameworks. Riyadh’s strategy follows: buy capacity bilaterally, give the Mecca framework operational content without testing the clause, keep the Iran channel open and tie US purchases to deliveries. The analysis is limited by the unverified treaty texts and the unknown outcome of the October meetings.
SOURCES
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Furkan Mahmut Tameroglu