After reading through this collection of "What-If?" stories, I can tell that I will not be holding on to this too much. Although the stories themselves are pretty good for the pulp novel status. Overall, a majority of the stories in this book are too defeatist in nature. The actual event though horrible and a loss for the US probably would not of lead to some of the time-lines that some of these authors pose. A number of them list the West Coast of the US being over run or captured. Finally, as others have stated the appendices listed are the good parts of this book. They explain the realities behind the attack, a time line of the attack, and finally an explanation of possible alternitives and the chances of them affecting the outcome of the attack. Possible better alternative histories of the attack on Pearl Harbor could be found in the book "Rising Sun Victorious" or in the books "What-IF and What-If 2"

An anthology of allohistories, that is, "what-if" stories based on the attack on Pearl Harbor. Like all anthologies, some stories are superb, some are weak, but overall the level is quite high. The only flaw, and it isn't a serious one, lies at the hands of the editors in their selection and organization of the stories. I'll leave the weakest part of the collection, Part 1, for last.
Part 2, 'Alternate Actions', are the stories by Pineiro, Reasoner, Dietz, and Hallanhan. These are the most traditionally "what-if" stories, hinging on a minor event causing a major change in result. Three are very good, and one, Reasoner's 'The East Wind Caper' is outstanding. A hard-boiled private eye (see Bogart in the role) stumbles onto the Japanese plot and saves the day. Well told, tightly paced and humorous.
Part 3, 'Alternate Aftermaths', contains stories by DuBois, Tillman, Allyn, and Keith. Of these, Keith's 'A Terrible Resolve' is the best, a tale of Japanese victories which lead the Empire up to the beaches of California before the success of the Manhatten Project and the actions of American kamikazi bombers, turn the Imperial Navy back.
A Postscript by Kupfer, which posits a Nazi victory over both America and Japan, is the most chilling story in the book.
The Appendices give an excellent historical background of the real world event, of the military and diplomatic realities which the allohistorians in the anthology had to manipulate for our entertainment.
Now, the worst for last, and as I previously said, it isn't too bad. Part 1, 'Alternate Architects', has the four stories by Hawke, Geraghty, DeFelice, Gorman. Very little allohistorical content in any of these, and what little there is, is only background color. Mostly these four just rehash old conspiracy theories about Roosevelt and/or Churchill knowing that the attack was going to happen and allowed it to go on in the hopes American would enter the war against Germany. I've got no problem with this belief, though I think, like most conspiracies, the proponents are assuming malice where simple incompetence is enough of an explanation. My problem with these stories is that so much of the tale is given over to rehashing the arguements, lecturing the reader on why the plot really did happen, that the stories are just plain boring. The editors could have had a much stronger anthology by leaving this part out and putting more of the rest in.
One observation, something that gave me a small grin. When reading the stories, watch for similarities between them. Variations on the phrase "cigarette, cigar, and pipe smoke" pops up in an awful lot of stories. I suspect the editors handed our a very detailed background guide to the authors, and some of them lifted material out of it verbatim.

This is one of the very best collections of alternate world histories that I have read and one I would use in the classroom were I still teaching. However, the stories as good as they are take second place to two very thoughtful essays by experts at the end of the book. Paul Thomsen gives an excellent diplomatic perspective of what went right and what went wrong in events leading to the attack. The greatest praise must go to historian William Forstchen who sums up the "The Realities of an Alternate Pearl Harbor". He brings out things that most of us either did not know or did not fully understand. It is his premise that even in the worst case scenarios all going against us, a third wave of attack destroying the oil tanks stored at Pearl which would keep us out of the Pacific for a year, the sinking of the three carriers that were away at the time of the attack which would mean no victories at Midway or the Coral Sea, the taking over of the base with veteran Japanese soldiers which would lose us Hawaii, and even the bombing of the Panama Canel which would take a year to rebuild, we would still have prevailed. Maybe the war would have been a year or two longer, but American moral resolve and production would have won out in the end. We were heavily devalued by most of the Japanese command and they would not foresee that in the American gestalt there is a sense of morality that makes us fight for what we see as not just territorial goals, but for freedom. In doing so we believe in complete victory. If anything, the Japanese would have been worse off to have gone beyond their success at Pearl. A year longer to get started would have meant more production of weapons on our part and by 1946 we would have had more than three atomic bombs. We likely would have laid waste to Japan to pay back for the conquest of Hawaii, the bombing of Panama, and raids on California. As it was, the Japanese were surprised at the resolve we did show. They thought we would be forced to compromise and negotiate a peace. They were as surpised as Muslim fanatics must be today in seeing our reaction to the attack on the Twin Towers in New York and the Pentagon in Washington D.C. and related actions. We prevailed then, we will now.