Ongoing war with Russia, persistent lack of consensus among NATO allies, and explicit opposition from the United States continue to block any realistic path to Ukrainian membership before 2027. The July 2026 Ankara summit produced a €70 billion aid pledge and recognized Ukraine as a security contributor but omitted membership language or an invitation, while former commander Valery Zaluzhnyi publicly stated in early August that Kyiv fails to meet alliance standards and will not join. Traders price the outcome near-certainly against accession given these structural barriers, the requirement for unanimous ally approval, and the absence of a Membership Action Plan or fast-track mechanism. A rapid ceasefire with ironclad security guarantees or a sudden shift in U.S. policy remain the main low-probability developments that could alter the timeline.