"People important enough" certainly thought a Pearl Harbor raid was possible. Until November the Fleet was on high alert and patrol patterns were flown that covered the area 1AF launched from. An attack at that time would have been spotted and probably would have found at least half the Fleet at sea.
BUT - In Winter the North Pacific is very stormy and no fun at all. The USN couldn't have made the raid thhat the IJN did, neither could the RN. When Winter hit, the "people important enough" felt that they were safe in relaxing a bit. The Fleet had been on War Alert status for six months, and ships and a/c were in dire need of long-postponed maintenance - not to mention crews (especially the Patrol Wing guys) needed a break too.
So the Fleet went off alert, and Patrol sectors shifted to basically ASW work south of Oahu. The Carriers were used to deliver planes to outposts instead of covering the Battle Line - all the CVs being away was why Kimmel had the whole Battle Line in PH that weekend; normally half would be at sea.
So the bottom line is that the USN was definitely alert for a PH raid until the weather made one impossible - except it wasn't impossible for the IJN.
The fact that Intelligence was 100% right about what the Japanese were doing in SE Asia distracted from Pearl too. We were watching the invasion fleets in the South China Sea and could not conceive that the Japanese would do the invasions without CV air cover.
from post #55,
http://208.84.116.223/forums/index.p...ic=13339&st=40