Turner made the decision not to send Kimmel details of the intercepted Japanese diplomatic communications which pointed strongly to an imminent air or sea attack on the Pacific Fleet's base at Pearl Harbor. Kimmel testified after the war that had he known of these communications, he would have maintained a much higher level of alert and that the fleet would not have been taken by surprise by the Japanese attack. A historian of the attack on Pearl Harbor, Professor Gordon Prange, wrote in "Pearl Harbor: The Verdict of History" that, even allowing for Kimmel's desire to exculpate himself, this was correct. Prange wrote: "If Turner thought a Japanese raid on Hawaii ... to be a 50-percent chance, it was his clear duty to say so plainly in his directive to Kimmel ... He won the battle for dominance of War Plans over Intelligence, and had to abide by the consequences. If his estimates had enabled the U.S. to fend off ... the Japanese threat at Pearl Harbor, Turner would deserve the appreciation of a grateful nation. By the same token, he could not justly avoid his share of the blame for failure."