The role of the Defence Forces is to defend the State against armed aggression, to provide Aid to the Civil Power (meaning in practice to assist, when requested, the Garda Síochána, who have primary responsibility for law and order) and to carry out other such duties as may be assigned to them from time to time. This can include search and rescue, air ambulance service, Ministerial Air Transport Service, assistance on the occasion of natural and other disasters and assistance in connection with the maintenance of essential services. The Defence Forces also participates in various national ceremonies throughout the year.