The Mecca Joint Defense Agreement, signed in August 2026 by Saudi Arabia, Turkey, and Pakistan, establishes a mutual security framework modeled on collective defense principles, with an attack on one treated as an attack on all. Recent activation of its mechanisms in early October amid Houthi threats and attacks on Saudi infrastructure has accelerated institutional steps, including appointment of a secretary-general and commitments to troop deployments and defense cooperation. Potential expansion remains open, with Egypt studying legal and constitutional issues after Turkish statements signaling interest, Bangladesh indicating positive consideration, and Syria reviewing options. No formal accessions have occurred to date, though parliamentary ratification requirements in member states and regional diplomatic alignments with actors such as Qatar or Iran could influence timelines through year-end. Traders monitor diplomatic consultations, committee outcomes, and security developments in Yemen and the Gulf for signals of momentum.