Sir Robert Menzies
"World War I broke out during the years when Menzies was pursuing the law course at Melbourne University. It was considered at the time a fair thing if two boys out of a family of four went to the war. Menzies's two elder brothers enlisted and went overseas after a family conference in which it was agreed that Menzies should not enlist but should complete his law course. Compulsory military training within Australia was then in operation and Menzies had become a lieutenant in the Citizen Forces. He continued to hold this commission until his period of compulsory service ended on his attaining the age limit."
Sir Percy Joske, Sir Robert Menzies, 1894-1978 - a new, informal memoir, 1978 p 18.