By an order of 11 December, the Western Defense Command became a theater of operations; on 20 December, a similar order provided for an eastern theater along the Atlantic coast.” By these acts, defense received priority over all training activity in both coastal zones, which were now raised to a new category of defense (Category C) in recognition of the fact that minor attacks were not only possible but probable. It will be noted that it was not anticipated that enemy forces could bring to bear any sustained attack on the continental area, but, as Pearl Harbor had so forcefully demonstrated, a single and well-directed blow could inflict serious injury.

That the chief focus of attention fell first on the Pacific rather than the Atlantic coast is explained by the former’s particularly exposed position following the Pearl Harbor attack. Concentration of some of the larger aircraft plants in that region appeared to offer especially tempting bait for a Japanese raid. Fortunately, news of the start of war did not come as a complete surprise to the military forces there. The warning message sent by the War Department to the Western Defense Command on 27 November 1941 indicating that negotiations with Japan in effect had terminated and that war was probable, had resulted in an acceleration of measures being taken to provide an aircraft warning service. Defense arrangements were further facilitated by the fact that air force and anti-aircraft artillery units, and civilian volunteers working with the warning service, were at the outbreak of war taking positions in California for an exercise scheduled to begin on 11 December.

Once the news of the Japanese attack had been received on the mainland, the Fourth and Second Air Forces, which shared responsibility for defending the West Coast, readjusted their forces to provide maximum protection for the major cities. In co-operation with the Navy, offshore patrols were promptly instituted to provide warning against carriers and to combat submarines. The aircraft warning service was put into operation, with civilians hurriedly manning their observation posts. Amateur radio stations were ordered off the air, and unnecessary civilian flying was prohibited. The War Department ordered the immediate movement of reinforcements for the Pacific coast by air and fast trains. The supply of heavy bombers was so limited that it was not found possible to immobilize any large number by assigning them to stations along the coasts. Locally based air units therefore consisted in large part of fighter aircraft, to which were added and aircraft artillery, barrage balloons, and searchlights. The first reinforcement to reach the Pacific coast consisted of planes of the 1st Pursuit Group, which arrived at San Diego on 8 December; by 22 December this entire P-38 group had been transferred from Michigan to California. An additional augmentation of pursuit strength was provided in mid-December by the temporary assignment to the Fourth Air Force of a Marine unit, Air Wing 1. Meantime, antiaircraft artillery units had begun to reach the West Coast from inland stations, and some regiments which were at ports of embarkation were diverted to coastal defense assignments.

As these and other forces took up their defensive positions, coastal communities suffered from an “invasion fever” which first showed itself with the calling of an alert in San Francisco on 8 December. In the afternoon of the 8th, rumors of an enemy carrier off the coast led to the closing of schools in Oakland. That evening, while residents of the Bay area were having dinner, radio broadcasting suddenly ceased, and this was followed by a blackout which lasted nearly three hours. in the absence of adequate preparations, sirens on police cars were used to warn the people, and self-appointed neighborhood wardens rushed from door to door to help enforce the blackout. Reports reaching Washington of an attack, on San Francisco were regarded as credible, but news dispatches soon characterized the affair as a test and announced that California had “caught its breath again.” The Army, however, insisted that radar stations had tracked airplanes approaching the coast from a distance 100 miles at sea. The continuity of the tracking convinced officers that the planes were hostile, and Lt. Gen. John L. DeWitt of the Western Defense Command strongly denounced those who treated the alert lightly. In the San Francisco News of 10 December he was quoted as follows: “Last night there were planes over this community. They were enemy planes! I mean Japanese planes! And they were tracked out to sea. You think it was a hoax? It is damned nonsense for sensible people to assume that the Army and Navy would practice such a hoax on San Francisco.” Newspapers, impressed with these statements, carried banner headlines announcing that the “Army Warns City Danger Near.” A similar message had been carried to a national audience on 8 December when Fiorello La Guardia, head of the Office of Civilian Defense, told the radio public: “I do not want to unduly alarm my fellow citizens, but I want to be realistic. The situation is serious. We must not underestimate what happened twenty-four hours ago.”

Disturbing rumors of enemy threats continued to mount on 9 December. Early that morning unidentified planes were reported off southern California, and the Eleventh Naval District ordered preparations made to repulse a raid by sea or air. Later the Navy relayed to the AAF a “red hot tip” which announced that thirty-four enemy vessels were standing off the coast near Los Angeles, waiting for the fog to lift before stage an attack. Army planes were dispatched and found that the alarm had been occasioned by the presence of a group of American fishing boats. Later in the day a report told with convincing detail of a “Japanese cruiser 20,000 yards off the west tip of Catalina Island.” Other witnesses insisted that a cruiser and three destroyers, flying Japanese flags, had been spotted off the coast. This of course was the period when whales were mistaken for enemy submarines, and when floating logs were bombed by inexperienced and overeager aircrews.

Such rumors and alerts were not confined to the Pacific coast. On 9 December an air raid warning, the first of the war, swept New York City and the northeast states. At noon, advices were received that hostile planes were only two hours’ distance away. Fighter aircraft from Mitchel Field took the air to intercept the raiders, and radio stations left the air. Since there was no system for warning the public —New York’s air raid sirens were not installed until February 1942 —the police took the initiative in spreading news of the alert. As a precautionary measure school children were hurriedly sent home.—No general hysteria was noted, but the warning was taken for the real thing on Wall Street, where a wave of selling on the exchanges brought security quotations down hundreds of millions of dollars in the worst slump of the stock market since the collapse of France. The alarm spread to Boston, where police shifted heavy stores of guns and ammunition from storage vaults to stations throughout the city, and where industrial establishments were advised to prepare for a raid.

The many alerts of this period reflect the inexperience of both the public and the defense forces. To some critics they indicated a deliberate attempt by the Army to frighten the public in order to stimulate interest in war preparations. Before accepting this view, however, it should be noted that many of the reports of unidentified aircraft, leading to precautionary blackouts, resulted from mechanical difficulties with new radar equipment and from the understandable mistakes of inadequately trained personnel. Further, there is every evidence that Army commanders were genuinely convinced that the danger of attack, especially against the West Coast, was very real. Military men knew better than the layman how limited were the defenses against air attack. Along the Pacific coast in December 1941 there were, for example, only forty-five thoroughly modern fighter planes to defend a coast line which extended for 1,200 miles, and along which were located such important aircraft plants as those of Boeing in Seattle, Douglas and Lockheed in Los Angeles, and Consolidated in San Diego. In heavy bombers, the defenders were even less well equipped; for at the close of 1941, there were only ten such planes stationed along the entire coast and the number within reach for concentration against an enemy force was indeed limited. Although there were seventy-five medium bombers at hand, their short range cut down their usefulness against the type of attack expected. Moreover, during late 1941 crews of both fighters and bombers were handicapped by an acute shortage of ammunition.

To reconstruct the problem as it appeared to air officers at the time, let us assume that the report of the presence of thirty-four Japanese ships off the California coast on 9 December 1941 had proved to be true. With what forces could so threatening a surface fleet have been opposed? There is good evidence on this point, for the Fourth Air Force actually issued an order to “ attack and destroy” the enemy task force. By good fortune, fourteen bombers destined for the Southwest Pacific were in the vicinity; but it was found that the machine-gun turrets on the planes would not operate, that there was no adequate supply of oxygen for high-altitude operations, that only a few 300- and 600-lb. bombs were on hand, and that the bombers would have to enter an engagement without fighter support. How effective this force—which was larger than any normally stationed along the coast would have been against a major enemy fleet must be left to the imagination, but competent authorities were convinced that a vigorous attack would have overwhelmed American air units at any of the chief points of defense along the western seaboard.

In spite of the grave concern for the safety of the West Coast, the first attack on a land objective in the Americas actually was directed against Aruba, in the Caribbean. On this small Dutch-owned island, and on neighboring Curacao, were located large refineries which processed oil from wells in Venezuela and currently accounted for one-third of the United Nations’ supply of high-octane gasoline. In May 1940 the British had furnished small garrisons for the islands, but the increased danger after Pearl Harbor led the Anglo-American planners at the ARCADIA conference to decide that larger forces of U.S. troops were needed. Two flights of light bombers from the Caribbean Air Force accordingly were sent to Aruba and Curacao in mid-January 1942, but attempts to send ground forces encountered diplomatic difficulties. At the end of January, President Roosevelt advised the President of Venezuela that, in deference to the latter’s objections, the United States would delay the dispatch of troops; but he indicated that the situation was so serious that steps would have to be taken to safeguard the vital refineries. Public announcement of the troop movement was made on 11 February.

Early in the morning of 16 February, aggressive enemy submarine action in the Caribbean area began with an attack on shipping off the harbor at San Nicholas, Aruba. After destroying two tankers, a submarine surfaced and shelled buildings of the Standard Oil refinery and then moved upshore for further attacks on shipping. The damage to the refinery was only superficial, but a torpedo which landed on shore exploded the next day, killing four men. Attempts by Army planes to bomb the submarine were apparently unsuccessful. In any case, the air patrols were powerless to prevent a second attack on Aruba on 19 February and additional nuisance shellings of shore installations in Puerto Rico on 2 March 1942 and of a refinery on Curacao on 19 April.

The initial attack on Aruba prompted President Roosevelt to warn the nation that enemy ships could shell New York City, or enemy planes drop bombs on Detroit. Secretary [of War Henry] Stimson added that the public might as well prepare itself to accept “occasional blows, ” because the Army was determined not to disperse its forces in small fragments to serve as security garrisons. The New York Times, in an editorial on 20 February, pointed out that American seaboard cities were well within the enemy’s reach, but that the only danger was that attacks might create a popular demand for protection at all costs. The real need, it was suggested, was for the perfection of the defense machinery already in existence. This raised the question of the adequacy of the national air defenses; a few days later, events along the West Coast provided a not too reassuring answer.

During the course of a fireside report to the nation delivered by President Roosevelt on 23 February 1942, a Japanese submarine rose out of the sea off Ellwood, a hamlet on the California coast north of Santa Barbara, and pumped thirteen shells into tidewater refinery installations. The shots seemed designed to punctuate the President’s statement that “the broad oceans which have been heralded in the past as our protection from attack have become endless battlefields on which we are constantly being challenged by our enemies.” Yet the attack which was supposed to carry the enemy’s defiance, and which did succeed in stealing headlines from the President’s address, was a feeble gesture rather than a damaging blow. The raider surfaced at 1905 (Pacific time), just five minutes after the President started his speech. For about twenty minutes the submarine kept a position 2,500 yards offshore to deliver the shots from its 5 1/2 -inch guns. The shells did minor damage to piers and oil wells, but missed the gasoline plant, which appears to have been the aiming point; the military effects of the raid were therefore nil. The first news of the attack led to the dispatch of pursuit planes to the area, and subsequently three bombers joined the attempt to destroy the raider, but without success. The reluctance of AAF commanders to assign larger forces to the task resulted from their belief that such a raid as this would be employed by the enemy to divert attention from a major air task force which would hurl its planes against a really significant target. Loyal Japanese Americans who had predicted that a demonstration would be made in connection with the President’s speech also prophesied that Los Angeles would be attacked the next night. The Army, too, was convinced that some new action impended, and took all possible precautions. Newspapers were permitted to announce that a strict state of readiness against renewed attacks had been imposed, and there followed the confused action known as “the Battle of Los Angeles.”