Question: Peter Isaacson served in a branch of the military in World War II that was originally formed in what year?

Related documents: [0]  [DOC] The Royal Australian Air Force (RAAF), formed March 1921, is the aerial warfare branch of the Australian Defence Force. It directly continues the traditions of the Australian Flying Corps (AFC), formed on 22 October 1912. The RAAF provides support across a spectrum of operations such as air superiority, precision strikes, intelligence, surveillance and reconnaissance, air mobility, and humanitarian support. [END] 
[1]  [DOC] Peter Stuart Isaacson, AM, DFC, AFC, DFM (31 July 1920 – 7 April 2017) was an Australian publisher and decorated military pilot. He was the owner of Peter Isaacson Publications, publisher of various trade journals and suburban newspapers including the "Southern Cross" and the "Sunday Observer" in Melbourne. During World War II, he served in the Royal Australian Air Force (RAAF) as a pilot with RAF Bomber Command and was awarded the Distinguished Flying Cross, the Air Force Cross and the Distinguished Flying Medal. [END]  
Answer: 1921
1921