[1] After working at different positions in the Turkish Land Forces Staff Lieutenant Colonel Doğu joined the National Intelligence Agency on 14 September 1954.

[2] He was one of the pupils of German military and intelligence officer Reinhard Gehlen.

[2] Doğu became a staff colonel and was named as the undersecretary of the National Intelligence Agency on 27 August 1962.

[1] The agency began to collect information for the National Security Council which had been established with the new constitution put into force in 1961.

[3] Prime Minister Nihat Erim and Deputy Prime Minister Sadi Koçaş found that Doğu was heading a secret unit within the National Intelligence Agency.