“A surprise that should not have been.”
It really wasn’t totally a surprise. The attack might have been, but not the fact that war was coming. A couple of years before Pearl Harbor, the U.S. really started building up facilities at Pearl Harbor. That caused a work boom for construction labor. My father-in-law moved from Kauai to Honolulu to work as a worker on construction projects; they built things like new aircraft hangars, etc. So everybody in Hawaii knew that that the U.S. was preparing for a potential war and at some point things could get bad, but I don’t think anyone in Hawaii thought Japan would have the gall to actually sneak attack a major U.S. naval facility the way it did. I think most folks assumed that the Japanese attack on America would have come somewhere in Asia like the Philippines.
In 1941 we didn’t have an aerial torpedo that could arm in shallow water and assumed that the Japanese didn’t either. Pearl Harbor is shallow water.
The Japanese employed radio silence well and we didn’t know that their fleet was headed our way. The “sneak attack” was just that.
In the years before WWII some American Naval cadet had written a paper describing how to go about an attack like Pearl Harbor. The Japanese made a practice of reading the papers of our bright students.
Which itself was judged not warranting the resources needed to defend it in the light of other locations.
True. Like 9111. But that new fanged thing called radar might have been of some help.
https://en.wikipedia.org/wiki/SCR-270_radar#Use_of_SCR-270_radar_at_Pearl_Harbor
Unit s/n 012 was at Opana Point, Hawaii on the morning of the seventh of December 1941 manned by two privates, George Elliot and Joseph Lockard. That morning the set was supposed to be shut down, but the soldiers decided to get in additional training time in since the truck scheduled to take them to breakfast was late. At 7:02 they detected the Japanese aircraft approaching Oahu at a distance of 130 miles (210 km) and Lockard telephoned the information center at Fort Shafter and reported “Large number of planes coming in from the north, three points east”. The operator taking his report passed on the information repeating that the operator emphasized he had never seen anything like it, and it was “an awful big flight.”
The report was passed on to an inexperienced and incompletely trained officer, Kermit Tyler, who had arrived only a week earlier. He thought they had detected a flight of B-17s arriving that morning from the US. There were only six B-17s in the group, so this did not account for the large size of the plot. The officer had little grasp of the technology, the radar operators were unaware of the B-17 flight (nor its size), and the B-17’s had no IFF (Identification friend or foe) system, nor any alternative procedure for identifying distant friendlies as the British had developed during the Battle of Britain. The raid on Pearl Harbor started 55 minutes later, and signaled the United States’ formal entry into World War II a day later.
The radar operators also failed to communicate the northerly bearing of the inbound flight. The US fleet instead was fruitlessly searching to the southwest of Hawaii, believing the attack to have been launched from that direction. In retrospect this may have been fortuitous, since they would have met the same fate as the ships in Pearl Harbor had they attempted to engage the vastly superior Japanese carrier fleet, with enormous casualties.
After the Japanese attack, the RAF agreed to send Watson-Watt to the United States to advise the military on air defense technology. In particular Watson-Watt directed attention to the general lack of understanding at all levels of command of the capabilities of radar- with it often being regarded as a freak gadget “producing snap observations on targets which may or may not be aircraft.” General Gordon P. Saville, director of Air Defense at the Army Air Force headquarters referred to the Watson-Watt report as “a damning indictment of our whole warning service”.