Upon leaving Malaya in 1963, he attended the Imperial Defence College in London, before returning to Canberra as Deputy Chief of the General Staff with the rank of major general. In the 1966 New Years Honours, Hassett was upgraded to a Commander of the Order of the British Empire, and also awarded the Malaysian Pingat Jasa Kebaktian (Meritorious Service Medal) for his services in Malaya.
Following his departure from Malaya in 1963, Hassett attended the Imperial Defence College in London before returning to Canberra as Deputy Chief of the General Staff with the rank of major general. He was subsequently recognized in the 1966 New Years Honours and received the Malaysian Meritorious Service Medal for his contributions in Malaya.