I read the book. IIRC At Dawn deals primarily with the diplomatic intelligence lead-up to the war. Prange, I believe wrote three books on Pearl Harbor and I think another dealt more with the military side of things. I thought it was excellent, but its a long, dry read.
1) did Roosevelt (and his key advisors, both civilian and military) have reason to believe that the Japanese were planning for an attack on Pearl Harbor - the answer to that is unequivocably yes;
Depends on what you mean by reason to believe. Certainly in a global sense one can say yes - everybody knew some reasons why it was a possibility - about war-gaming the attack on Pearl in 1940, the previous CINC had objected to moving the fleet to Pearl because of greater vulnerability, everyone knew that the Japs had started their first war with China and the war with Russia with a knockout blow to the enemy fleet - the fact that the location of the carriers was not pinned down while the rest of the fleet was. Kimmel had better knowledge of this than Marshall or Roosevelt. (He famously asked Layton shortly before the attack: "you mean those carriers could be rounding Diamond Head right now?" The
possibility they might attack Pearl is why Pearl was included with Panama and the Philippines in the "war warning message of November 27th.
A related question is whether the US leaders believed the Japanese would attack the US somewhere, - and the answer to that is unequivocably yes. Did the US leaders expect an attack on or about December 7th - based on alerts issued by the US, and intel they possessed - unequivocably yes.
Absolutely. The rationale of the war warning on November 27th was that an attack was coming soon.
PEARL HARBOR WARNING
27 November Message Sent by Navy Department, 27 November 1941:
This dispatch is to be considered a war warning. Negotiations with Japan looking toward
stabilization of the conditions in the Pacific have ceased and an aggressive move is
expected within the next few days. The number and equipment of Japanese troops and the organization of the naval task forces indicates an amphibious expedition against either the Philippines, Thai, Kra Peninsula, or possibly Borneo. Execute an appropriate defensive deployment preparatory to carrying out the tasks assigned in War Plan 46 [The Navy’s war plan]. inform district and army authorities. A similar warning is being sent by the War Department.
It's why Halsey went to a war status when he sailed to Midway. The ironic thing is that the military was more concerned about an attack on Pearl Harbor six months earlier than they were in December - in December they though they knew what the Japs were doing and didn't think they would dare attack the Phillipines and Singapore without the support of carrier based air. But keep in mind, Marshall insisted that the Hawaii commanders get exactly the same war warning they were sending to the Philippines which they knew would be in the first attack.
Message sent by Chief of Naval Operations, 3 December:
Highly reliable information has been received that categoric and urgent instructions were
sent yesterday to Japanese Consular posts at Hongkong, Singapore, Batavia, Manila,
Washington and London to destroy most of their codes and ciphers at once and
burn...confidential and secret documents.
As far as Turner anticipating the attack on Pearl Harbor - that's Turner revisionist ass-covering. If there was an intelligence failure Turner is one of the central goats. Here's a quote re the views of one of the intelligence insiders most convinced that we should have anticipated the attack on Pearl:
And I Was There: Pearl Harbor and Midway – Breaking the Secrets, by Rear Admiral Edwin T. Layton, USN (Ret.), with Captain Roger Pineau, USNR (Ret.) and John Costello
New York: William Morrow Quill, 1985. Pp. 596. Illus., maps, notes, biblio., index. 10.95. ISBN:0-688-06968-1.
Edwin T. Layton was probably the biggest unsung hero of the Pacific Theater of World War II. He was an intelligence officer for Admirals Husband E. Kimmel and Chester W. Nimitz during the war, and he was deeply involved with the high-ranking officers from the unprovoked sneak attack on December 7, 1941, to Japan’s unconditional surrender on September 2, 1945. Layton’s memoirs are an inside story, which he began writing thirty years after the end of World War II, when enough materials had been declassified. Layton’s views are intriguing, particularly where he lays blame for Pearl Harbor. In one of the major bombshells, Layton lays the blame upon then-Rear Admiral Richmond Kelly Turner, who was director of war plans.
Given our lack of response to the actual outbreak of hostilities in the Phillipines for 6-7 hours, when the agreed plan was to respond immediately with an airstrike on Taiwan, it is hard to imagine what it would take to get a response from a military which after being warned that "This dispatch is to be considered a war warning. Negotiations with Japan looking toward stabilization of the conditions in the Pacific have ceased and an aggressive move is expected within the next few days." respond by closing down the radar for the weekend (and the following one when the attack occurred), continuing to return the ships to port for the weekend with the crews all given liberty, and keeping all the ammo under lock and key.
Nations rarely suffer surprise for lack of warning, but fall victim with astonishing
regularity because they fail to respond to warning.
Richard Betts
Surprise is a basic and recurring event in human life. Still, neither the repeated
occurrence of surprises nor our assumption that life has surprises...makes us any
less vulnerable to its impact. In most cases of surprise we do not ignore the
probability of a potential occurrence but rather tend to reject it as unlikely. Therefore,
when it actually does happen, it takes us “ by surprise” since we had expected it
to occur later or in a different place or manner. Sometimes our imagination is too
limited even to entertain the possibility of surprise, preventing us from
envisaging the event in any way.
Ephriam Kam: Surprise Attack. 1988. p. 7
Warning is a necessary but insufficient condition for avoiding surprise. Without
response, warning is useless. Warning is evidence filtered through perception;
response is action (alert, mobilization, and redeployment) designed to counter an
attack.
Richard Betts. Surprise Attack. 1982. p. 87.
The policy-maker, unlike an academic analyst, can rarely wait until all the facts
are in...He is very often under strong pressure to do something, to take some
action, even if all the facts are not yet available to him or where a careful
assessment of current data would provide useful results.
The capacity of human beings to deal with situations of vast complexity is very
limited. The human mind needs a highly simplified “map” of a situation if it is
going to be capable of taking any action or making a decision. These maps are
subjective, generally being based on and springing from deeply held values.
Robert Bowie, as quoted in Ernest R. May, Knowing One’s Enemies. 1986. p. 4
It was hard enough for Americans to believe that the Japs would have the nerve to attack the United States. To believe they would attack Pearl with the heart of their naval air force at the same time as attacking the heart of British Far Eastern power and the Philippines was beyond imaginative resources of any American of that time (during Jim Crow and European domination) to consider as a
likely possibility.