This market will resolve to "Yes" if active military personnel officially affiliated with any NATO or EU country enter Ukraine for combat-related military purposes directly pertaining to the ongoing conflict with Russia by December 31, 2025, 11:59 PM ET. Otherwise, this market will resolve to "No". For military personnel to qualify toward a "Yes" resolution, they must be 1) officially acknowledged as active military by the NATO or EU entity or member state they are affiliated with; 2) be publicly acknowledged by NATO or an EU-affiliated entity to have entered Ukraine for a combat-related military purpose directly pertaining to the ongoing conflict with Russia. For military personnel to qualify toward a "Yes" resolution they need be active duty and acknowledged as described above. Participation in a combat role is necessary for this market to resolve to "Yes" (e.g. military personnel providing training or intelligence support would not qualify toward a "Yes" resolution, however drone pilots or infantry directly attacking Russian troops, or soldiers targeting and downing missiles from Ukrainian soil would qualify toward a "Yes" resolution). The primary resolution source for this market will be official information from NATO, the EU, or member states of either entity, however a consensus of credible reporting will also be used.