OPERATION STORM. By John J. Geoghegan. 496 pages. $28.

Secret operations during World War II span many topics in many regions. Few can rival Japan’s Operation Storm in scope of daring and dedication. Author John J. Geoghegan did a good job (and a tremendous amount of research) bringing this little-known story to life.

As a follow up to the attack on Pearl Harbor, Admiral Isoroku Yamamoto, commander-in-chief of the combined fleet, developed a plan to attack (by air) major U.S. cities, including the Atlantic coast. The original purpose of the attacks was to be more psychological than physical, and would be carried out by aircraft launched from large I-400 class submarines. Operation Storm was a longshot attempt to break America’s will to fight a protracted war with Japan.

At 400 feet long and more than 6,000 tons, the I-400 submarines were almost 100 feet longer three times heavier than U.S. submarines. I-400s were designed to travel great distances, a necessary requirement to threaten any U.S. city along the Atlantic coast. Eighteen I-400s were to be built with each carrying three Aichi M6A1 Seiran floatplanes. Bigger is not always better.

By the time construction began on the first I-400 in early 1943, the outlook of the war for Japan had changed. To further complicate the secret program, Admiral Yamamoto was killed on April 18, 1943. As the war continued to go badly for Japan, I-400 construction was eventually reduced to three; only two (I-400 and I-401) entered service.

During their construction, the mission for I-400 submarines also changed, but was no less risky; an attack on the Panama Canal. Geoghegan puts a nice focus on the key (and controversial) Japanese personalities associated with the I-400 program. He concludes their courage and perseverance could not overcome the decisions made by the Imperial Japanese Navy High Command.

Although the three submarines and their handful of aircraft would have no impact on the course of the war, the U.S. Navy had no knowledge of their existence or agenda. “Operation Storm” is an interesting read that takes us to some “what if” possibilities we often like to debate.

Reviewer David A. Clark is senior curator at the Patriots Point Naval & Maritime Museum.