The Mecca Joint Defense Agreement, signed in August 2026 by Saudi Arabia, Türkiye, and Pakistan, establishes a collective-defense framework modeled on NATO Article 5 and explicitly open to additional members through consensus of the core parties. Its entry into force in November 2026 after Turkish ratification has focused attention on accession talks, with Egypt described as a natural partner facing technical issues and Syria reported in active negotiations. Gulf states including Qatar, Kuwait, and the UAE have drawn interest amid regional security realignments, while formal accession requires official signing or joint announcements rather than expressions of intent. Scheduled committee meetings and bilateral diplomacy through 2027 represent key catalysts that could shift probabilities based on verifiable progress.