Key point: The Imperial Japanese needed inside knowledge of America's naval base.
“You are probably the nearest to war that you’ll ever be without actually being in it,” said Commander Harold M. “Beauty” Martin as he addressed his men on the morning of December 6, 1941, at Kaneohe Naval Air Station on Mokapu Peninsula, located less than 15 miles east-northeast of Pearl Harbor. “Keep your eyes and ears open and be on the alert to every moment,” said the well-respected commander.
One fellow who was keeping his eyes wide open that day was Japanese spy Takeo Yoshikawa. He closely observed the Pacific Fleet at anchor in Pearl Harbor on the south side of Oahu late in the afternoon from vantage points at Aiea Heights and the Pearl City Landing. Later the same day he sent a coded report to Tokyo noting that the U.S. Army had ordered equipment for barrage defense balloons, but none was yet on scene, and he opined that torpedo nets probably were not in place to protect the battleships at anchor in Pearl Harbor. “I imagine that there is considerable opportunity left … for a surprise attack,” he added, as the clock continued ticking.
Meanwhile, Commander Martin’s somber, cautionary message earlier in the day was being widely debated by the American sailors, a number of whom belittled the racial and intellectual capabilities of the Japanese, especially their ability to handle fast-moving aircraft. Some even argued that any aggressive Japanese actions against the United States would be quashed within two weeks.