[4] He participated in the World War II as an officer in the Royal Indian Navy on the behalf of the United Kingdom on the European front, and was sent to attend the Britannia Royal Naval College after the end of World War II in 1945.

[4] Hassan was among the first twenty naval officers who decided to join the Royal Pakistan Navy (RPN) as a Lieutenant with a Service number PN.0073 that was listed in the seniority list sent by the Royal Indian Navy to Pakistan's Ministry of Defence.

[6] There, he accompanied Governor of Punjab, Abdur Rab Nishtar, on a Hajj mission led by Pakistan Navy in Mecca, Saudi Arabia.

: 140 [11] Many of his requests to retaliate against the Indian Navy were rebuffed by the Air Marshal Abdul Rahim Khan who reportedly quoted: "Well, old boy, this happens in war.

": 89–90 [11] After the war, he was subsequently dismissed from his military service and relieved from the command of the Navy on 22 December 1971 along with the chiefs of army and the air force.

[4] He, along with Lieutenant-General Gul Hassan and Air Marshal Abdul Rahim Khan were forcefully retired from their commission on 3 March 1972 in a stand up military trial led by the combined JAG Branch.