Private John L McDermott, enlisted into The King's Own Royal Regiment (Lancaster) as a 16 year old in 1936. He served with them in Palestine from 1936 to 1939 and in Iraq in 1941.He was recommended for a Distinguished Conduct Medal, but awarded a Military Medal, for conspicuous gallantry in August 1941, when he carried a wounded comrade under heavy enemy fire and also made repeated runs across open ground to resupply a mortar detachment with ammunition.

In 1942 Pte McDermott transferred to the Corps of Military Police. He qualified as a military parachutist on Course 137 at RAF Ringway on 9 to 23 October 1944 and was posted to 6th (Airborne) Divisional Provost Company CMP.

Pte McDermott married Private Vivien Hall in November 1944, shortly after she had returned from serving overseas for several months.

He was transferred to 1st Airborne Division Provost Company and  deployed to Norway in May 1945 for Operation Doomsday.