Based on prior learning could the attract on Pearl Harbor have been prevented why

The Japanese attack on Pearl Harbor on 7th December 1941 is a significant event in United States history. It's speculated that the United States could have prevented the attack on Pearl Harbor and the ensued war with the Japanese. After the war documents belonging to Joseph Grew, the American ambassador to Japan, were discovered. According to the papers ambassador Grew had obtained intelligence from the Peruvian ambassador to Japan which confirmed their was a plot to attack the Pearl Harbor. The message was received almost a year before the attack. Grew passed the info along which seemed superficial which he seemingly believed it to be unlikely. He later blamed the attack and the United States involvement in World War II on President Roosevelt.