Pinehas joined SWAPO's armed wing, the People's Liberation Army of Namibia, in 1980 and was deployed to the Cadet Military Academy in Cuba which he completed in 1981 and was appointed deputy commander there.

His career in the Namibian Defence Force started in 1993 after Namibia's independence when he was inducted with the rank of Lieutenant.

In 1994 he was appointed as the commanding officer of the 1st Air Wing squadron with the rank of Major.

In 1998 he was promoted to the rank of lieutenant colonel and appointed as the chief of staff of the Air Wing.

[2] On the 31 March 2020 he was promoted to air marshal and appointed as Chief of Defence Force becoming the first non Army General to occupy the position.