Lea became commanding officer of the Special Air Service in 1955 and saw action again in Malaya. He went on to be commander of 2nd Infantry Brigade in 1957, deputy military secretary in 1960 and General Office Commanding &lt;a href="42nd%20%28East%20Lancashire%29%20Infantry%20Division"&gt;42nd (Lancashire) Division/District&lt;/a&gt; of the Territorial Army in 1962. He was given command of the armed forces in Northern Rhodesia and Nyasaland in 1963 and became director of operations in Borneo in the spring of 1965, just before a pivotal battle with Indonesia at Plaman Mapu during the Indonesia-Malaysia confrontation. His last appointment was as head of the British Defence Staff in Washington, D.C. in 1967 before retiring in 1970.