Career
He joined the South African Army in 1924. During World World War II he commanded the 3rd Infantry Brigade in North Africa, for which he was awarded the Defence Science Organisation and then briefly commanded 2nd Infantry Division. As fortress commander, Klopper was forced to surrender Tobruk and its garrison to Axis forces on 21 June 1942.
He escaped from captivity in 1943 and was officially exonerated for the Tobruk disaster.
He was OC of Northern Command in 1945.