Sailors watch the explosion of the USS Shaw in the background, during the Japanese attack on Pearl Harbor, Hawaii, Dec. 7, 1941. (AP)

Pearl Harbor: Did FDR and the Navy know what was coming?

Looking back on the days before Dec. 7, 1941 -- and how FDR prepared for a war he thought might be inevitable

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David Kaiser
April 6, 2014 2:59PM (UTC)
Excerpted from "No End Save Victory: How FDR Led the Nation Into War" 

The rulers of Japan and Germany, rather than Franklin Roosevelt, chose the moment at which the United States would enter the world war. Japan had decided back in early July to undertake the southward advance at the risk of war with the United States, the Japanese Navy had insisted on including an attack on the United States in its military plans, and Hitler had decided to declare war if Japan attacked. But Roosevelt obviously did not shrink from entry into the world war in early December 1941. His administration had adopted the objective of defeating all the Axis powers and had begun the military and the economic planning to achieve it. He had shared that objective publicly with the American people, a large majority of whom now accepted war as inevitable. In October, fully three-quarters of respondents to a Gallup poll said either that the United States would inevitably get into the war in Europe or that the United States was in the war already. Stark’s and Marshall’s last-minute memorandum suggested that the early months of the war might be perilous indeed, but the administration’s Victory Program could not possibly be implemented in peacetime. With the Germans now halted before Moscow, ultimate victory over the Axis seemed at least possible, and the time to enter the war had come.

From Monday, December 1, through Thursday, December 4, new Magic intercepts conveyed Tokyo’s instructions to its diplomatic representatives in London, Singapore, Manila, Hong Kong, Washington, and various Chinese cities to destroy their codes and other publications. On December 6 in Tokyo—December 5 in the United States—the Foreign Ministry told the Embassy in Washington to await the delivery of a long message giving the Japanese reply to Hull’s November 26 note. War was obviously imminent. We must now look at both the manner in which the Japanese had decided to begin it, and the reasons why the key commanders in the Far East disregarded their warnings and so much available evidence and remained almost completely unprepared on the morning of December 7.


Roosevelt’s November 25 statement that the Japanese “were notorious for making an attack without warning” was a simple historical fact. Against China in 1894, Russia in 1904, Manchuria in 1931, and China in 1937, the Japanese had struck without any preliminary announcement or declaration of war. In the first two cases, they had begun the war with at least partially successful attempts to destroy enemy fleets. Both the Japanese and U.S. navies had adopted the doctrines of Admiral Alfred Thayer Mahan, who believed that great battles between fleets decided wars.

Japanese Admiral Isokuru Yamamoto had the responsibility for planning the war against the United States, and he had proposed a surprise attack on Pearl Harbor in May 1941 and war-gamed it in September. On October 20, Admiral Osami Nagano, the naval commander-in-chief, had agreed to the carrier-based attack. The attacking task force of six aircraft carriers, escorted by battleships, cruises, destroyers, and submarines, had gotten underway at dawn on November 26, Japan time—that is, nearly twenty-four hours before Hull handed Nomura and Kurusu his maximum demands in Washington. Although the task force might conceivably have been recalled, it observed radio silence, and U.S. military and naval intelligence had not yet broken the Japanese naval code, as opposed to the diplomatic Purple code, in any event.

On the other side, U.S. authorities had been discussing a possible Japanese attack on Pearl Harbor for at least eighteen months. In mid-June 1940, a variety of rumors about impending Japanese action in the Pacific had moved General Marshall to order General Charles Herron, then the Army commander in Honolulu, to put his forces on alert against an air attack. Admiral Stark, meanwhile, had ordered Admiral Richardson, the fleet commander, to put the fleet to sea for a few days in the direction of the Panama Canal. The Navy maintained an “outer air patrol” around the islands to a distance of 180 miles for at least five weeks.

On November 22, 1940, after British torpedo bombers had sunk several Italian warships at anchor in their base at Taranto, Stark wrote Richardson asking whether Pearl Harbor needed torpedo nets to protect the fleet from a Japanese surprise attack. Richardson replied on January 8 that such nets would cause too much trouble, that he lacked ships and planes for continuous air search, and that the probability of an attack would not justify it. At the turn of the year 1940– 1941, Stark also exchanged letters with the commander of the Hawaiian Fourteenth Naval District regarding the adequacy of Pearl Harbor’s antiaircraft defenses, “in view of the probability of an early surprise attack by carrier aircraft if Japan decides to make war on the United States.” Knox wrote Stimson a detailed and accurate summary of the problem on January 24, acknowledging that the Navy might deal with a combined bomber and torpedo bomber attack by locating and engaging the carriers before they arrived but making clear that he did not necessarily expect to be able to do so and asking the Army to provide better antiaircraft and fighter defense. Stimson on February 7 promised more modern fighter planes, more antiaircraft guns, and an “air warning system”— presumably radar— by June.

On March 24, Admiral Husband Kimmel, who had replaced the crusty Admiral Richardson in January, wrote a long memorandum on his campaign plan for Admiral Stark. “The war may be initiated by enemy attack without warning,” he wrote, “and these attacks may take any form. Such attacks may be directed against shipping, outlying possessions, naval units, or against Pearl Harbor itself.” Kimmel had already raised the same possibility in another letter he and his predecessor Richardson had jointly drafted for Stark on January 25. In response, the War Department had sent up-to-date pursuit planes and some B-17 bombers to both Hawaii and the Philippines. But despite some discussions with the British officers from the Royal Air Force, most American authorities had no idea of how many pursuit planes and radars they would need to defend installations like the Philippines, Pearl Harbor, and the Panama Canal from a carrier-based attack. Admiral Turner in late October circulated detailed British advice on the need to disperse and camouflage aircraft in the Philippines from the moment they arrived, but Stark passed it on to the Philippines much too late to do any good.

In November, as war with Japan seemed imminent, all eyes seemed to focus on the Japanese southward advance. Roosevelt on November 26 personally warned the High Commissioner of the Philippines, Francis Sayre, of possible Japanese moves, including attacks on the Burma Road, Thailand, the Malay Peninsula, the Dutch East Indies, and the Philippines. All turned out to be correct. The United States was well aware of Japanese forces moving southward, but on November 7 a Naval Intelligence report placed the Japanese aircraft carriers in home waters. At least one high-ranking naval officer in Washington still thought the Japanese would probably avoid attacking U.S. possessions altogether. Most critically, however, Admiral Kimmel in Hawaii did not believe that war was going to break out at all.

Earlier in 1941, Kimmel had repeatedly made clear that he did not feel ready to fight the Japanese, especially after the transfer of some of his cruisers, battleships, and a carrier to the Atlantic. At least since the spring of 1940, the Navy had assumed that the Japanese would for some time be occupied with taking the Philippines and Guam if war broke out and that that might allow the U.S. Fleet to seize bases in the Marshall or Caroline islands. Kimmel was charged in ABC-1 with advancing toward the Japanese mandated islands— the Gilberts, Marshalls, and Carolines— in order to draw Japanese naval forces away from the Malay barrier, but because of the losses he expected to incur from enemy submarines and land-based aircraft, he informed Stark in July that he could promise nothing more than raids on the Marshalls. Kimmel took no new action in response to the war warning of November 27, and his Army counterpart, General Short, merely put his forces on alert against sabotage. On the morning of Saturday, December 6, Kimmel and his staff met with a journalist, Joseph Harsch of the Christian Science Monitor, who had reported from Europe earlier in the year and had just arrived in Hawaii. After Kimmel and his staff questioned Harsch for some time about events in Europe, Harsch asked them whether there would be war in the Pacific. Harsch first published Kimmel’s reply forty years later.

“Since you have been traveling,” Kimmel said, “you probably don’t know that as of six days ago the German high command announced that the German armies in Russia had gone into winter quarters. That means that Moscow is not going to fall to the Germans this year. That means that the Russians will still be in the war in the spring. That means that the Japanese cannot attack us in the Pacific without running the risk of a two-front war. The Japanese are too intelligent to run the risk of a two-front war unnecessarily. They will want to wait until they are sure that the Russians have been defeated.” Kimmel’s staff, Harsch wrote, seemed very relaxed, and no one seemed to disagree.


Kimmel argued to the end of his life (and his descendants continue to do so) that no one had warned him of an imminent attack on Pearl Harbor. That is true, but what is more important is that he had decided, himself, that Japan was not going to attack the United States at all. Kimmel essentially confirmed this in his testimony before several investigations of the Pearl Harbor attack, after he had been relieved of duty and reduced in rank. Shortly after the attack, testifying before the Roberts Commission— the first investigative body convened to look into the Pearl Harbor disaster—he said that he did not expect the United States to be imminently involved in war on December 6. He also said that had he known of the close tabs the Japanese consulate in Honolulu were keeping on the presence of ships in Pearl Harbor on December 6, “I would have ordered all units to sea, because the best dispositions against surprise attack can be effected with the fleet at sea.” Although the war warning of November 27 had listed the Philippines and Borneo among the possible Japanese targets, Kimmel believed they would move only into Thailand and force the United States to react. During the June 1940 alert, Admiral Richardson had sent out air patrols around Hawaii for several weeks, but Kimmel said he did not do so because he did not have enough planes for an effective search and because it was more important for him to preserve them for offensive action after war had broken out. Several years later, testifying before the congressional investigation, Kimmel said that while the war warning of November 27 had initially made a strong impression on him, after several days had passed without incident, he became less and less convinced that Japan was going to attack the United States. Had he thought that a carrier-based attack on Pearl Harbor was imminent, he said, he would have put the fleet out to sea and instituted the fullest possible air search.

All this confirms Joseph Harsch’s recollection of Kimmel’s attitude. The Admiral had said himself that if Japan went to war with the United States, it might well do so by making a surprise attack on the fleet at Pearl Harbor. Even though General Short had the responsibility for the defense of Pearl Harbor itself, Kimmel was responsible for his fleet, and his testimony indicates that he realized that he had a particular responsibility not to allow his fleet to be sunk in harbor at the beginning of a war. It is possible, of course, as many authorities have pointed out, that the results of the Japanese attack might have been even worse had Kimmel believed war was imminent and sent the U.S. Fleet out to sea. Had the Japanese located their targets at sea, they might have sunk many ships in deep water, including some American aircraft carriers, giving them undisputed command of the Pacific for a very long time. As it was, all but two of the battleships hit by the Japanese on December 7 were eventually repaired and saw extensive action in the war, and U.S. carriers were entirely missed because they were on a mission at sea. Washington indeed withheld the specifics of the Magic intercepts from field commanders for security reasons, but Stark and Marshall had given the field commanders their conclusions based on those intercepts. Kimmel disregarded his superiors’ warning that war was imminent and relied instead on his own belief that it was not— a terrible mistake for which he was duly disciplined.

Washington authorities were much better informed than Kimmel and Short about the possibly imminent outbreak of war—although they had no information specifically suggesting an attack on Pearl Harbor—but an unfortunate lapse prevented them from getting their best information to Hawaii until literally the last minute. On December 5 Tokyo had warned the Embassy to expect an important message, and that fourteen-part message, rejecting Hull’s note and breaking off the talks—although not formally announcing either a break in relations or war—began arriving in the middle of the day on December 6. Army and Navy intelligence had decoded the first thirteen parts by about 9:30 p.m. The message reviewed the negotiations from the Japanese point of view, accusing the United States of refusing to budge from impractical principles, of preparing to attack Germany and Italy, and maintaining its hegemony and imperialistic exploitation in the Pacific.

A Navy courier brought the thirteen parts of the message to the White House between 9:30 and 10:00 p.m., where he found Harry Hopkins, newly emerged from the Naval Hospital, with the President. “The President,” said the courier years later, “then turned toward Mr. Hopkins and said, in substance—I am not sure of the exact words, but in substance—‘this means war.’ Mr. Hopkins agreed, and they discussed then for perhaps five minutes the situation of the Japanese forces.” Couriers then distributed the thirteen parts to other high civilian and military authorities. But when the fourteenth part, announcing that the Japanese now found it impossible to reach agreement through negotiations, arrived around midnight, Colonel Carlisle Dusenbury, the Army intelligence officer on duty, went home without distributing it. The same thing happened in Naval Intelligence. Not until the next morning did the fourteenth part, together with instructions for the delivery of the whole message at 1:00 p.m. the next day—7:00 a.m. in Honolulu—reach any senior officials. Marshall immediately dispatched another warning to Short in Hawaii, but it arrived while the attack was underway. Within an hour, hundreds of Japanese carrier planes had sunk two battleships—the Arizona and Oklahoma—for good, sunk or damaged six more, and badly damaged three cruisers and three destroyers. They also wiped out most of the Army’s fighters and bombers at Wheeler and Hickamfields.


The war broke out on the morning of December 7, Hawaii time, because the Japanese had decided to make war on the United States and Britain in order to create the Greater East Asia Co-Prosperity Sphere, including the Dutch East Indies, Thailand, Malaya, Burma, and the Philippines. The military and naval authorities in the Philippines, General MacArthur and Admiral Hart, seemed to have given as little practical attention as Kimmel and Short to the actual problems of detecting and evading or parrying a Japanese first strike. MacArthur evidently had trusted his own illusions, telling the High Commissioner in the Philippines and the British Admiral Sir Tom Phillips that the Japanese would not be able to attack the Philippines for several months. Although MacArthur had been informed on November 21 that Rainbow 5 now asked him to conduct air raids on any Japanese targets within range in the event of war, the general refused to order an American air strike on Japanese bases in Formosa even after news of the Pearl Harbor attack arrived. Devastating Japanese air attacks disabled most of Mac Arthur’s air force, including about half of his thirty-five B-17 bombers, many hours after the Pearl Harbor attack and four hours after Mac Arthur had discussed the situation by telephone with General Gerow in Washington.

When the news reached Washington, Roosevelt and his leading subordinates never thought of war against Japan alone. On the afternoon of December 7, FDR briefed congressional leaders and made clear he would ask for a declaration of war against Japan the next day. One Senator, Tom Connally of Texas, immediately predicted that Germany would declare war on the United States. Hull told British Ambassador Lord Halifax late on December 7 that he expected immediate German and Italian declarations of war on the United States as well. Roosevelt met Congress on December 8, calling December 7 a day “that will live in infamy,” and a declaration of war on Japan passed with only one dissenting vote in the House of Representatives, that of Congresswoman Elizabeth Rankin of Montana, an extreme right-winger and isolationist who had also voted against entry into the First World War in 1917. On that same day, December 8, Magic intercepts confirmed that Ribbentrop had promised the Japanese Ambassador that Germany would enter the war at once. Not for a moment had the administration thought of fighting the Japanese alone. Donald Nelson, the director of the Supply Priorities and Allocations Board (and soon to replace William Knudsen as the head of the war production effort), had been scheduled to make a nationwide radio broadcast on the evening of December 7. After checking with the White House, he went ahead with new language. “We must keep in mind,” he said, “that though the attack has been made by the Japanese it is in reality an attack upon us by the Axis powers. . . . We are face to face with an attack directed primarily from Berlin.”

Roosevelt gave a fireside chat on the evening of Tuesday, December 9, laying out the record of aggression in both Europe and Asia over the last ten years and speaking at length about the economic demands of war. Japan, he said, had begun the war after Germany had promised the Japanese the control of Asia and the Pacific. “We know also,” he said, “that Germany and Japan are conducting their military and naval operations in accordance with a joint plan. That plan considers all peoples and Nations which are not helping the Axis powers as common enemies of each and every one of the Axis powers. That is their simple and obvious grand strategy. And that is why the American people must realize that it can be matched only with similar grand strategy.” Battles in the Pacific, in Libya, in the Caucasus, and potentially in North Africa were all part of the same war. “Remember always that Germany and Italy, regardless of any formal declaration of war, consider themselves at war with the United States at this moment just as much as they consider themselves at war with Britain or Russia,” he said. The same newspapers that reported that speech on December 10 carried news from Berlin that a declaration of war was expected at any moment, and Hitler indeed proclaimed it to the Reichstag on December 10. Mussolini did the same in Rome.

The Supply Priorities and Allocations Board had met on December 8 and again on December 9. For some time Stimson had been pressing William Knudsen of the Office of Production Management on the question of whether the country could meet the Victory Program production targets on schedule, by July 1, 1943. On December 9 Knudsen had his answer. “We can’t meet them by July 1, 1943,” he said—“but we can meet them by July 1, 1944.”

The United States now faced the most critical military situation in its history as an independent nation. The Joint Board on December 8 agreed that the Japanese could now seize the Hawaiian Islands, speculated that some Japanese carriers might be on their way to bomb the almost undefended West Coast of the United States, and began frantically looking for planes and antiaircraft guns for the West Coast and Hawaii. Rather than execute the longstanding plan to strengthen the Navy in the Atlantic when the United States entered the European war, the Navy now had to withdraw units from the Atlantic to try to secure Oahu from a possible new Japanese attack. Partly as a result, the coming year of 1942 became by far the worst year of the whole war in the Battle of the Atlantic, with more than twice as many ships sunk in the North Atlantic than in 1941, and many more along the Atlantic and Gulf coasts of the United States. Although the Germans had now conceded that their campaign in the Soviet Union had halted for the winter, no one could guarantee that the Soviets would last out another year, or that the Germans would not occupy North Africa, or even that Britain would not be invaded in 1942. Yet now, just two days after Pearl Harbor, Knudsen had given Stimson the approximate date on which the decisive offensives against both Germany and Japan would begin. That was the fruit of eighteen months of planning, new contracts, new plant construction, labor mediation, and endless calculations at the Navy and War departments and among the economists at the Bureau of Research and Statistics at the OPM—the achievement of Stimson and Knox, Marshall and Stark, Knudsen and Hillman and Donald Nelson and Stacy May, and all the rest. And the whole process had been set in motion and carefully monitored by Franklin Roosevelt, who in July 1941 had ordered his more cautious military and naval leaders to prepare for the total defeat of both Germany and Japan.


Five years before, FDR had declared that his generation had a rendezvous with destiny. The climax of that rendezvous was now at hand, and Roosevelt and his colleagues’ work had ensured that the war that was just beginning would indeed have no end save victory.

Excerpted with permission from "No End Save Victory: How FDR Led the Nation Into War" by David Kaiser.  Available from Basic Books, a member of The Perseus Books Group.  Copyright © 2014. Reprinted with permission of the publisher. All rights reserved.

David Kaiser

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