Ongoing Russian military operations and the active conflict with Ukraine remain the dominant barrier to NATO accession, as full membership would require unanimous Allied consent and trigger Article 5 collective defense commitments amid unresolved territorial disputes. NATO summits through mid-2026, including the July gathering in Ankara, have reaffirmed an irreversible path to membership and expanded support mechanisms such as the NATO Security Assistance and Training for Ukraine while recognizing Kyiv as a security contributor, yet stopped short of any invitation or timeline. Statements from key capitals, including U.S. positions linking membership to postwar conditions, further constrain near-term prospects. Realistic shifts before 2027 would require a verified ceasefire, broad Allied consensus on reforms and borders, and de-escalation acceptable to all parties.