The late Roberta Wohlstetter's Pearl Harbor (google excerpt) is the must-read book, not only for Pearl Harbor but for 9/11 as well.  She explains the difference between background "noise" and the actual events, and how difficult it can be to determine which is what--especially when our own objectives are unclear.  She is particuarly acute on technological change and political will in shaping strategy.  Here is the Albert Wohlstetter website.  I was recently reminded that venerable American historian Edmund Morgan is her brother; here is her obituary, which refers to the work of her husband Albert, who was an important figure in the Cold War and the teacher of many a Washington DC defense intellectual and policy maker.