 [4] He served as the SAF's contingent commander for the International Force for East Timor (INTERFET) in 1999 and as the Director of Operations, Ministry of Health, during the 2003 severe acute respiratory syndrome (SARS) outbreak, he was involved in establishing the national contact and tracing system in Singapore.In 2010, Neo was appointed as the SAF's Chief of Defence Force (CDF) and was promoted from the rank of Major-General to Lieutenant-General.He was succeeded by Ng Chee Meng in 2013 when he retired that year.