The Japanese admiral who planned the Pearl Harbor attack got the idea from a British novel, says a new book examining U.S. and Japanese strategy in World War II.

Admiral Isoroku Yamamoto - who insisted on the 1941 surprise raid that destroyed much of the U.S. Pacific Fleet at its base in Hawaii - based his strategy on a book that had Washington buzzing when Yamamoto was Japanese naval attache here from 1926 to 1928, says author William H. Honan.The 1925 novel, "The Great Pacific War" by Hector C. Bywater, begins with a surprise Japanese attack in 1931 that wipes out much of the U.S. Asiatic fleet.

Honan's book, "Bywater: The Man Who Invented the Pacific War," went on sale earlier this month in England. It is due for U.S. publication in February with the title "The Man Who Knew Too Much: How Hector C. Bywater Invented the Great Pacific War."

Bywater was a British secret agent in Germany who later became a leading expert on the world's navies in the pre-jet age, when national strength was measured in battleship tonnage.

From 1920 to 1940, he wrote for newspapers and magazines on both sides of the Atlantic, covered major naval disarmament conferences in London and Washington and published several books.

It was more than coincidence that the course of the war was predicted in Bywater's novel, says author Honan, currently the New York Times' chief cultural correspondent.

Honan presents exhaustive research intended to show that Bywater's writings profoundly influenced Japanese strategists led by Yamamoto, supreme commander of the Imperial Navy combined fleet and architect of the Pearl Harbor attack.

"The Great Pacific War" was translated into Japanese and for a time was required reading for Japanese navy officers. It also inspired Japanese imitations that switched endings and had the Japanese winning the war.

Yamamoto spent a year at Harvard University in 1919 and returned to America seven years later with the rank of Navy captain for his Washington stint.

Back in Japan, Yamamoto in a lecture "adopted Bywater's ideas as his own," Honan says. The author adds that the Japanese naval officer in 1941 threatened to resign with his entire staff to force acceptance of his plan "to eradicate the American naval presence" in mid-Pacific at the start of the war.

This was precisely Bywater's conception, Honan says, and Yamamoto enhanced it with something not available at the time "The Great Pacific War" first appeared - massed aircraft carriers and their planes, "the daring tactical innovation" of Japanese naval air chief Minoru Genda.

Yamamoto followed Bywater "so assiduously in both overall strategy and specific tactics at Pearl Harbor, Guam, the Philippines and even the Battle of Midway that it is no exaggeration to call Hector Bywater the man who invented the Pacific War," Honan adds.