NATO has two Immediate Reaction Forces: the Standing NATO Maritime Groups composed of the SNMG1 and the SNMG2; and the Standing NATO Maritime Mine Countermeasure Groups (SNMCMG1 and SNMCMG2).
SNMG1 and SNMG2 function according to the operational needs of the Alliance, therefore helping to maintain optimal flexibility. Their composition varies and they are usually composed of between two and six ships from as many NATO member countries.
