Emergency military

An emergency military is a type of major military organization that handles a nation's governance at a time of crisis. It is often confused with military rule which is permanent. It may also refer to a military force established in a time of emergency, or an emergency operational force in case of a major invasion, crisis or unrest of indigenous populations. An emergency military is one of the major military organization types and usually defines the entire aspect of a nation's military force from militia to Navy.

United Nations Space Command
The United Nations Space Command serves as humanity's temporary emergency military government, having been given control over humanity's civilian governing bodies, the Unified Earth Government and the Colonial Administration Authority, during the Human-Covenant War. Following the UNSC's absorption of the Colonial Military Administration early in the 26th century, the UNSC Defense Force served as humanity's primary (if not only) means of defense against the Covenant.