On this date, December 6th, 1941, the Japanese Fleet was 250 miles north of Ohau. Having traveled 11 days over 4000 miles, undetected, they prepared to attack the US Pacific Fleet at Pearl Harbor. All six of Japan’s first-line aircraft carriers, Akagi, Kaga, Soryu, Hiryu, Shokaku and Zuikaku, were there. With over 420 planes, the ships constituted the most powerful carrier task force ever assembled. The Pearl Harbor Task Force also included fast battleships, cruisers and destroyers, with tankers to fuel the ships during their passage across the Pacific, a total of 30 capital ships. How did the Kido Butai, which set sail on November 26th, 1941, get all the way to the Hawaiian Islands without being seen?
The Japanese maintained radio silence all the way to the launch point, and was using radios on shore in Japan to simulate radio traffic between fleet units, which led the Americans to believe the carriers were still in home waters. So we weren’t actively looking for them. We thought we knew where they were. They chose a northerly route which was not heavily traveled by merchant traffic, air or sea, and lucked out by having a storm follow them most of the way so they would have been hard to spot. A Russian transport, Uritsky, carrying US-built M2 tanks and other war materials, passed on December 5th. All the fleet guns were pointed at the Urisky, but Nagumo decided to let it go due to the non-aggression pact they had with Russia. Whether the Russian transport reported the task force is not known. Assuming they did, the Russians decided not to report it to the United States. Radar was pretty much non-existent and certainly not trusted in the early 1940s. It’s range was not very wide either. All of these factors made the Mobile Striking Force, the Kido Butai, virtually invisible on it’s way to Hawaii.
The US military believed that the Hawaiian islands were too far away for the Japanese to mount an attack. Even Yamamoto knew that his ships would have to be refueled in route, which was a very tricky business, especially in the storm they encountered. After the attack, the US Navy still believed that the attack had to have come from the south, like the Marshall Islands in the central Pacific. The fact that the Imperial Japanese Navy was able to launch an attack on Pearl Harbor led to the panic that ensued about a possible attack on the west coast of the United States.
An advanced submarine task force launched miniature subs early on the morning of December 7th. The USS Ward spotted one of these subs trying to sneak into Pearl Harbor and sank it. When they reported it, the officer on duty didn’t believe it and did not report it. When the first wave of 180 bombers was picked up by an experimental radar crew on Opana Point, it was dismissed by another naval officer as a flight of B-17s that were expected that morning from the mainland. The Americans even thought the bombing of Schofield Barracks and Wheeler Airfield was a mistake by military personnel. Many thought someone was going to be a in a lot of trouble for accidentally loading live ammunition on practice runs.
It appears that all of these incidents were nothing more than coincidences. Without the detailed planning and nearly flawless execution of the preparations, the attack on Pearl Harbor would not have succeeded. Joseph Goebbels, the Nazi Propaganda Minister, wrote in his diary on December 8th, “Japan has suddenly taken action……the mood among the German people has risen considerably.”