This chapter explores attitudes and actions of Greek and Slovenian diplomacies towards the European External Action Service (EEAS). It examines the two countries' attitudes towards the EEAS, its leadership and its relations with other institutional actors, including the national diplomacies. The core objective of Slovenian foreign policy after gaining independence was to consolidate its place in the Euro-Atlantic security community in order to deflect any potential security threat from its immediate neighbourhood. The only new area in which there has been significant potential for Greece has been in regional energy cooperation given the discovery of energy resources in the eastern Mediterranean. Slovenia and Greece share a foreign policy goal, namely to ensure the European Union (EU) perspective of the countries of Southeast Europe. The empirical research we conducted suggested that the Hellenic Ministry of Foreign Affairs is currently still in the process of accustoming itself with the operation of the EEAS.