[1] During World War I, he joined the Venizelist Provisional Government of National Defence and fought in the Macedonian front as commander of the 4th Archipelago Regiment.

[1] Following the disastrous defeat of the Greek army in Anatolia by the Turkish nationalist forces in August 1922 and the subsequent outbreak of a military revolt, he was recalled to active service as commander of the 7th Infantry Division.

[3] He then assumed the post of Inspector of the Infantry in the General Staff, until March 1935 when he was involved in another unsuccessful Venizelist coup attempt.

[1] During the Axis Occupation of Greece in World War II, Manetas was arrested by the Italians and imprisoned in concentration camps in Italy and Germany.

He was elected a Member of the Greek Parliament in 1950 for Athens, and served as Minister for Supply and Distribution in the Nikolaos Plastiras cabinet.