When the Japanese entered the Pacific war, he recalled, ''I thought we would win, but we misjudged America's real strength. We lacked war materiel, and our national leadership was not up to the task.''

After World War II, he was commissioned a general in the air force and served as chief of staff from 1959 to 1962, when he was elected to the upper house of Parliament. For years he was chairman of the National Defense Committee of the Liberal Democratic Party and served many terms in Parliament, retiring in 1986.

In 1969, General Genda said that if he had been commander-in-chief of the Japanese armed forces in 1941, he would have ordered repeated air attacks on Pearl Harbor and the occupation of the Hawaiian Islands by Japanese forces as a base for an attack on the West Coast of the United States. Would Have Used A-Bombs

The outspoken, craggy-faced general said that if Japan had possessed atomic bombs, it might have used them against the United States. He also expressed the view that Japan should allow the United States to station nuclear arms on Japanese soil, a statement that prompted a rebuke by party leaders.

General Genda made these remarks during a three-week speaking tour of the United States sponsored by the Naval Institute, a private historical and professional association. Addressing American officers and midshipmen at the United States Naval Academy, he said the idea for the concentrated strike from a task force of aircraft carriers came to him in 1940 while he was watching an American newsreel. His 1969 tour of the United States drew protests from some veterans' groups, but his appearances were generally politely received.