This market will resolve to "Yes" if active military personnel officially affiliated with any NATO member state enter Yemen for combat-related military purposes directly pertaining to the ongoing conflict in Yemen by December 31, 2026, 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 NATO or the member state they are affiliated with; 2) be publicly acknowledged by NATO or the member state to have entered Yemen for a combat-related military purpose directly pertaining to the ongoing conflict with the Houthis. For military personnel to qualify toward a "Yes" resolution they must be active duty troops 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 infantry engaging Houthi forces, or personnel conducting combat operations against the Houthis from Yemeni soil would qualify toward a "Yes" resolution). Only members of the regular armed forces of a NATO member state will qualify toward a "Yes" resolution. Foreign fighters, private military contractors, mercenaries, or any other personnel recruited, paid, trained, equipped or directed by a NATO member state who are not members of that state’s armed forces will not qualify, regardless of whether they operate under its command or on its behalf. Members of a NATO member state’s armed forces operating as part of a coalition, including a Saudi-led coalition, will qualify. Personnel must be physically present on the terrestrial territory of Yemen, including its internal waters. Air or naval operations conducted from outside Yemeni territory, including air strikes, missile strikes, drone strikes and overflights, will not qualify toward a "Yes" resolution. The primary resolution source for this market will be official information from NATO and the governments and defense ministries of NATO member states; however, a consensus of credible reporting will also be used.