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. NATO summits through 2026 have reaffirmed long-term support and an eventual path but issued no invitation, while recent comments from former Ukrainian commander Valery Zaluzhnyi highlighted shortfalls in military readiness. Traders assign only a 3-4% chance of membership by the deadline, reflecting these entrenched hurdles. A swift ceasefire, rapid reforms meeting alliance benchmarks, or unexpected diplomatic consensus could still shift timelines, though such developments face significant procedural and geopolitical constraints.