 Muang Muang had resigned in early 1961, and as a consequence Serong's influence was limited from this time, During this period he worked to prepare the Burmese for a border war against China.While in Burma Serong's expertise brought him to the attention of the US Central Intelligence Agency (CIA), and as a result he was later invited to supervise counter-insurgency programs in Vietnam.In February 1962 he wrote to Pollard, by then CGS, to suggest the deployment of a small team of Australian officers under his command to South Vietnam to work with the US advisory group there.