Primary responsibility for law and order, including the protection of the internal security of the State, rests with An Garda Síochána. Among the roles assigned to the Defence Forces is the provision of Aid to the Civil Power (ATCP) which, in practice, means to assist An Garda Síochána when requested to do so.
On occasions, the Defence Forces are deployed to Shannon Airport in an ATCP role in support of An Garda Síochána. When deployed in an ATCP role, Defence Forces personnel remain under the operational command of a Defence Forces Officer at all times. For security and operational reasons, it is not considered appropriate to make any further comment in relation to how such operations are conducted.