On 31st December, 1915, A torpedo was fired at Ionic II during World War I whilst she was on military duty in the Mediterranean; it missed her "by a matter of feet". She survived the conflict and returned to commercial service on 31st January 1919 after release from the Liner Requisition Scheme. Ionic II remained on the White Star/Shaw, Savill & Albion New Zealand joint service until Cunard White Star was formed in 1934 when she was transferred outright to SSA.

Ionic was scrapped in 1937.