Greece became a NATO member in 1952 and is host to several facilities including the NATO Deployable Corps Greece (NDC-GR) located in Thessaloniki, the Combined Air Operations Centre (CAOC 7) in Larissa, the Multinational Peace Support Operations Training Center (MPSOTC) in Kilkis, the NATO Maritime Interdiction Operational Training Centre (NMIOTC) at the naval base of Souda Crete, NATO Missile Firing Installation (NAMFI), Athens Multinational Sealift Coordination Centre (AMSCC), and the Naval Base of Souda.

For the Hellenic Republic, the participation in humanitarian assistance and peace support missions is a high priority. Greece has contributed to the ISAF mission, KFOR, and Operation Active Endeavor. The Hellenic Composite Battalion, manned by 120 personnel and 47 vehicles, is responsible for erecting technical support buildings at Kabul International Airport (KAIA), reinforcing camp security, training of Afghan Soldiers, and distributing of humanitarian aid. Greece has decided to increase personnel to the reconstruction of Afghanistan with a new OMLT in October 2009 and two medical teams will contribute to the ISAF operation regarding Afghanistan national elections. Greece has contributed personnel to SEEBRIG Headquarters that undertook command of the Kabul Multinational Brigade and ran the Hellenic Field Surgery Hospital that functioned operationally from within KAIA.

The Hellenic contingent in Kosovo conducted hundreds of reconnaissance, escorting, and control missions, but its main achievement was discovering a depot in which a great number of weapons and ammunition were hidden.

Since 2001, Greece has been participating in Operation Active Endeavour by protecting high value units and by conducting surveillance, maritime inspections, and maritime counter-terrorism operations. Greek Armed Forces also perform operations in support of the Greek population and have contributed a significant amount of resources and capabilities in search and rescue operations, disaster relief, bush fire fighting operations, and mobile military medical units.

In response to NATO's goal to become more agile and expeditionary, Greece reduced and restructured its forces to improve joint capabilities and to take advantage of current technologies. The restructure called for a smaller number of units to be manned at higher levels, assisted by increasing personnel establishments. The general staff is also being reorganized to promote better inter-staff cooperation, to improve defense planning processes, and to improve the use of allocated resources.

The Defence Planning Questionnaire determines the number of Armed Forces used for NATO issues, but the disposal of armed forces which are under national command must go through a political decision that is determined on a case by case basis.