Slow March to War -- The Backroom Buildups

The scenario had years a-building. Ever since the end of the Great War in 1918, U.S. Navy people had looked at Japan with increasing concern. By the 1920s, the Navy's quiet backroom War Plans office had begun to develop what became known as Plan Orange -- upgraded now and then, this was the scheme for countering a Japanese naval attack in the Pacific. During this period, a civilian journalist, British-born Hector C. Bywater, European naval correspondent for The New York Times, The New York Herald, and The Baltimore Sun, wrote two books, the latter titled "The Great Pacific War", in which he (prophetically) outlined how the Japanese would attack in the Pacific, notably at the Philippines. But the U.S. had been a major player in the postwar naval disarmament conferences, times seemed good, Americans wanted no further parts of warlike functions since the "war to end wars" had been fought, and funding for the Army and Navy was both small and begrudged. Despite the Navy's ships being largely obsolescent at best, the election of Herbert Hoover as President in 1928 saw no new naval ship funding at all during his Administration.

The subsequent 1932 election of Franklin D. Roosevelt made a Navy enthusiast President, a man who had served previously as Assistant Secretary of the Navy, as once had his older cousin, former President Theodore Roosevelt. Entering his first 4-year term as the Depression was hitting its dismal low, among Roosevelt's first moves was getting naval funding upped sharply, with new warships in mind. Among other changes, the former Plan Orange would become known as Rainbow, its regular upgrades numbered in sequence. The Fleet began to slowly improve. Its higher-ups' attention to intelligence, however, did not increase apace.

The halfway mark of Roosevelt's second term saw marked Navy improvement and enlargement, with numerous new warships of all types being designed and built, though the Army did not do nearly as well equipment-wise.

By this time, however, Naval Intelligence had had a young middle-grade officer in Japan as a naval attache -- Ellis M. Zacharias, who spoke the language and made it his business to meet people and learn things. He sent back numerous illuminating reports . But his recipients' offices were still small and backroomy; indeed, to be assigned to Naval Intelligence was considered almost a career dead end. However, by the time war broke out in Europe in September of 1939, cryptologists of the Army and Navy, working with the Department of State, had learned how to decrypt the supposedly impenetrable Japanese diplomatic code. To do this required a special machine as well as excellent knowledge of Japanese. Code-named the "Purple Machine", or simply "Purple", its product was called "Magic". This considerable accomplishment was most useful -- if it were analysed by experts and then one paid attention to it, which did not necessarily occur. That left the Navy a still-undecipherable Japanese code. Named JN-25, it was the one used by the Imperial Japanese Navy.

The gradual enlargement of Japanese activity, first in Manchuria in 1931, then in Formosa, and finally on mainland Chinese soil by the mid-1930s, the USN had been stirred to its keel by the unprovoked Japanese air attack on the little gunboat USS PANAY in the Yangtse River in 1937. From that moment on, more attention began to be paid to intelligence matters. But this was yet relative.

Japanese intelligence was still back-seated when war broke out in Europe in September of 1939. U.S. naval interest turned primarily to Nazi Germany and its vaunted Kriegsmarine, especially its U-boat threat in the Atlantic, a position enhanced by the President's own strong Anglophilism, and remembrances of the Great War among senior flag officers. One of these was Ernest J. King. Now a vice-admiral, his lifelong connections had been in the Atlantic sphere. In May of 1940, Nazi Germany suddenly blitzed across Western Europe in the wake of the "phoney war" period, further aggravating Navy attention.

The Navy Gets Friends

Meantime, Secretary of the Navy Frank Knox had become a firm friend of the very senior and influential Representative Carl Vinson, who had chaired the House Naval Affairs Committee since 1917. They had gloried in passage of their long-sought Bill creating a true two-ocean navy in mid-1940. Historically, the U.S. Navy had begun on the Atlantic. By the 1840s, it had made various Pacific voyages, the 1850s saw the opening of semi-medieval Japan by Commodore Matthew Perry, and the rapid growth of a steam-and-steel navy after the 1870s meant further Pacific attention, due to a need for coaling stations and bases. This became imperative after the Spanish-American War produced the Philippines and Guam. Withal, the Navy remained fundamentally Atlantean in outlook, even through the Great War. Though there were Pacific ships and postwar finally an official Pacific Fleet, these were offshoots of the basic navy, which remained Atlantic-oriented. This would now change radically.

Instead of one fleet in two divisions, there would be two complete fleets, each with its own wide oceanic responsibilities. Thus the Atlantic and Pacific Fleets became of equal "rank" and distinct focus. Of the latter, the distant Asiatic Fleet, which was less fleet than large squadron, was a subordinate part. Vinson was credited by the Navy itself with knowing more about the Navy than the Navy did, and was personally responsible for pushing through Roosevelt-era Congresses its increasing between-wars growth and preparedness. In 1940 one of these facets was naval aviation. Whether battleships were built or not, Vinson wanted at least a dozen new carriers, and 15,000 pilots and places to train them, and got the money. But it presented a problem. Over in the U.S. Senate, its Naval Affairs Committee found itself in the peculiar position of wanting to heavily finance rearming in the face of Navy cautions about overspending. Again, one facet was naval aviation. On 31 May, Stark was informed that the crucial need for training planes in the expansion programme meant delays in combat aircraft going to the enlarged Fleet, which specifically affected patrol squadrons. Stark took this calculated risk. One result was few big, long-ranging PBY "Catalina" patrol bombers for Pearl Harbor.

Meantime, Admiral James O. Richardson, in command of the Pacific Fleet, was ordered to move its headquarters from San Diego, California, to Pearl Harbor. He liked neither the move nor Knox, a former newspaper magnate. Knox visited Pearl Harbor and told the press that he believed the base "tremendously well defended" -- though he told others he knew its defences were inadequate, and that there was a lack of "war-mindedness" in the fleet, which Richardson took personally. He told Knox the Pacific Fleet should not base at Pearl Harbor, but back in its old home of San Diego. Knox did not agree, and on return to Washington shared this view with another friend, Secretary of War Henry Stimson, whose opinions and concerns were similar. Stimson told Knox that, as he saw it, any diplomatic easing-up on Japan by the U.S. would be seen as a weakness to be exploited.

In October, after a Washington conference, Richardson returned to Pearl Harbor ordered to assess all Army/Navy defences there. His report began by noting that "If war eventuates with Japan, it is believed easily possible that hostilities would be initiated by a surprise attack upon the Fleet or the Naval Base at Pearl Harbor." He further asserted that the priorities of such an attack would be, first, aerial bombing; second, aerial torpedoes; followed in order by sabotage, submarine attack, mining, and surface gunnery. He further urged that the Army increase its defensive aircraft and ground anti-aircraft capability, and establish an effective air-warning net in the islands. Knox passed this along to Stimson, who replied two weeks later expressing "complete concurrence as to the importance of this matter" and promised to send within six weeks thirty-one obsolete P-36 pursuit planes, fifty new -- but already obsolescent -- P-40 pursuit planes, increase the number of AA guns, and to deliver aircraft warning equipment by June.

In April, Knox, Stark, Stimson, Marshall, and King conferred with Roosevelt. King wanted more ships, and Stimson urged sending the entire fleet into the Atlantic. Marshall concurred, saying that in his view Pearl Harbor was invincible whether any ships were there or not, and noted in his diary that Knox agreed. The security of Pearl Harbor was not examined.

By early August of 1940 eight Purple machines had been built. Two each went to the Army and Navy, and British Prime Minister Winston S. Churchill got one. In January of 1941, a sixth Purple Machine went to Admiral Thomas Hart, commanding the Asiatic Fleet. The same month saw Knox and Stark among ten secrecy-sworn men who began to get personal copies of MAGIC intercepts. That summer, the seventh machine went to MacArthur in the Philippines. None were sent to Pearl Harbor, nor were their respective Army and Navy commanders made privy to direct Magic intercepts.