Ongoing conflict with Russia remains the dominant barrier to Ukraine's NATO accession before 2027, as alliance rules require unanimous member consent and conditions including interoperability standards and stable security that active hostilities undermine. The July 2026 Ankara Summit reaffirmed long-term support through €70 billion in aid commitments but issued no invitation, echoing prior declarations that membership occurs only when allies agree and criteria are met. Russia's explicit opposition, combined with statements from Ukrainian officials highlighting unmet military benchmarks, reinforces trader consensus reflected in the 96.5% probability for "No." A verifiable ceasefire or major diplomatic breakthrough enabling rapid consensus could theoretically shift timelines, though structural hurdles and the compressed 2026 window limit near-term prospects.