The past tense of Demobilize is demobilized.
verb. ['dɪˈmoʊbəˌlaɪz'] retire from military service.
verb. ['dɪˈmoʊbəˌlaɪz'] release from military service or remove from the active list of military service.
1. Verb, base form At this temperature, steel's atoms vibrate strongly enough to demobilize tiny magnetic zones called "domains" in the material.