During the Russo-Japanese War, he became famous for coining nicknames for each of the ships in the Russian fleet, to make identification and transmission of orders to the Japanese gunnery crews more understandable.

On his return, he instructed at the Naval Staff College, and in 1909 succeeded to the title of danshaku (baron) under the kazoku peerage system on the death of his foster father.

In December 1916, Abo was promoted to rear admiral and became chief of the first section of the Imperial Japanese Navy General Staff.

He subsequently served on the Supreme War Council and as part of Japan's delegation to the London Naval Treaty Conference in 1929.

Abo was a political moderate and a leading supporter of the Treaty Faction within the Imperial Japanese Navy, and hoped for a revival of the Anglo-Japanese Alliance through diplomacy.