A King's Commissioned Indian Officer (KCIO), Wadalia was educated at Aitchison College and the Prince of Wales Royal Indian Military College, Dehra Dun.[3] He subsequently attended the Royal Military Academy Sandhurst and was commissioned a second lieutenant in the British Indian Army on 31 January 1929, passing out fifth in the order of merit from 37 successful cadets.[4][5] He was formally appointed to the Indian Army as an officer with the 4/19 Hyderabad Regiment (now 4 Kumaon Regiment) on 13 April 1930.[6] On 1 March 1934, he transferred to the 16th Light Cavalry and was appointed a squadron officer.[7] He was appointed the adjutant on 1 January 1937.[8]
During the Second World War, Wadalia was appointed a GSO 3 in the Directorate of Military Training on 27 June 1941, under Brigadier Francis Tuker.[9] Advanced to a GSO 2 on 26 September and promoted temporary major in December,[10] Wadalia was transferred to the Directorate of Armoured Fighting Vehicles on 26 May 1943.[11] He served on the headquarters staff in the Persia-Iraq theatre and was mentioned in dispatches.[3][12] On 13 August 1944, he was appointed a GSO 1 on the staff, with the acting rank of lieutenant-colonel.[13] He was promoted substantive major (temporary lieutenant-colonel) on 31 January 1946.[14] On 23 December 1949, he was promoted temporary brigadier and given command of a brigade.[15]
^ abNanporia, N. J., ed. (1959–60). "Who's Who in India (Wadalia, Mohinder Singh)". The Times of India Directory & Yearbook, including Who's Who. The Times of India Press, Bombay. p. 1226.
^Sharma, Gautam (1996). Nationalisation of the Indian Army, 1885-1947. Allied Publishers Limited. p. 239. ISBN81-7023-555-3.