Marines of the 1st, 3rd, and 4th Defense Battalions standing guard in Hawaii, when the Japanese attack started, fought back as best they could. Few heavy weapons were yet in place, and ammunition remained stored on ship board, along with many of the guns. Nevertheless, these units had eight antiaircraft machine guns in action within six minutes after the first bombs exploded at 0755. By 0820, 13 machine guns were manned and ready, and they cut loose when a second wave of Japanese aircraft began its attack a few minutes later. Unfortunately, shells for the 3 inch antiaircraft guns did not reach the hurriedly deployed firing batteries until after the second and final wave of attacking aircraft had completed its deadly work. The Marines responded to the surprise raid with small arms and an eventual total of 25 machine guns, claiming the destruction of three aircraft during the morning's fighting.

    For decades before Japan gambled its future on a war with the United States, the Marine Corps developed the doctrine, equipment, and organization needed for just such a conflict. Although the Army provided troops for the defense of the garrisons on any of the smaller possessions that the Navy might use as bases at the onset of war; and seizing and defending the additional naval bases that would enable the United States to project its power to the very shores of Japan's Home Islands. A succession of ORANGE war plans ORANGE stood for Japan in a series of color-coded planning documents provided the strategy for the amphibious offensive required to defeat Japan and the defensive measures to protect the bases upon which the American campaign would depend.

    As a militaristic Japan made inroads into China in the 1930's, concern heightened for the security of Wake, Midway, Johnston, and Palmyra Islands, the outposts protecting Hawaii, a vital staging area for a war in the Pacific. Although actually atolls, tiny islands clustered on a reef-fringed lagoon, Wake, Midway Johnston, and Palmyra have traditionally been referred to as islands. By 1937, the Marine Corps was discussing the establishment of battalion-size security detachments on the key Pacific outposts, and the following year's War Plan ORANGE proposed dispatching this sort of defense detachment to three of the Hawaiian outposts -- Wake, Midway, and Johnston. The 1938 plan called for a detachment of 28 officers and 428 enlisted Marines at Midway, armed with 5-inch coastal defense guns, 3-inch antiaircraft weapons, and searchlights for illuminating targets at night, and machine guns. The Wake detachment, similarly equipped, was to be slightly smaller, 25 officers and 420 enlisted men. The Johnston Island group would consist of just nine officers and 126 enlisted men and have only the antiaircraft guns, searchlights, and machine guns. The plan called for the units to deploy by M-Day -- the date of an American mobilization for war -- in sufficient strength to repel minor naval raids and raids by small landing parties. In the fall of 1938, an inspection party visited the sites to look for possible gun positions and fields of fire and to validate the initial manpower estimates.

    Meanwhile, a congressionally authorized board, headed by Admiral Arthur J. Hepburn, a former Commander in Chief, Pacific Fleet, investigated the need to acquire additional naval bases in preparation for war. While determining that Guam, surrounded by Japanese possessions, could not be defended; the Hepburn Board emphasized the importance of Midway, Wake, Johnston, and Palmyra. As a result, during 1939 and 1940,Colonel Harry K. Pickett -- Marine Officer, 14th Naval District, and Commanding Officer, Marine Barracks, Pearl Harbor Navy Yard -- made detailed surveys of the four atolls.

    In 1940, the Army and Navy blended the various color plans, including ORANGE, into a series of RAINBOW Plans designed to meet a threat from Germany, Japan, and Italy acting in concert. The plan that seemed most realistic, RAINBOW 5, envisioned that an Anglo-American coalition would wage war against all three potential enemies, defeating Germany first, while conducting only limited offensive operations in the Pacific, and ultimately throwing the full weight of the alliance against Japan. Such was the basic strategy in effect when Japan attacked Pearl Harbor.

    The interest of the Marine Corps in base defense predated the proposal in the ORANGE Plan of 1937 to install defense detachments at Wake, Midway and Johnston Islands. Although the spirit of the offensive predominated over the years, both the Advanced Base Force, 1914-1919, and the Fleet Marine Force, established in 1933, trained to defend the territory they seized. In 1936, despite the absence of primarily defensive units, the Marine Corps Schools at Quantico, Virginia, taught a 10-month course in base defense, stressing coordination among aviation, antiaircraft, and artillery.

    The increasingly volatile situation in the Pacific, which led ultimately to war, the evolving ORANGE plan for a war against Japan, and the longtime interest of the Marine Corps in base defense set the stage for the creation of defense battalions to garrison the crescent of outposts stretching from Wake and Midway to Samoa. Influenced by American isolationist attitudes, Major General Commandant Thomas Holcomb decided to ask for funds to form new defensive -- rather than offensive -- headquarters, some advocates of the defense battalions may have felt that these new units were all the service would need by way of expansion, at least for now.

    Envisioned as combined arms teams capable of delivering intense firepower, defense battalions were expected to have their greatest impact in the kind of campaign outlined in the ORANGE plan. The Navy's seagoing transports provided strategic mobility for the defense battalions, but once ashore, the units lacked vehicles and manpower for tactical mobility. Because the battalion became essentially immobile when it landed, each member had a battle station, as on a ship, to operate a particular crew-served weapon or other piece of equipment. As configured in 1939 and 1940, a defense battalion could achieve mobility on land only by leaving its artillery, searchlights, and detection gear and fighting as infantry. Marine Corps defense battalions could operate as integral units in support of a base or beachhead, positioning their weapons and equipment to cover assigned sectors and meet specific threats. Moreover, they might form detachments with a size and armament suitable for a particular task, such as defending various islets within an atoll or protecting separate beachheads. Although relatively static when in place, the ability of the battalions to divide in this fashion provided a kind of flexibility that may not have been fully appreciated in 1939, when the basic concept placed one battalion, though of variable size, at a given place. Because a defense battalion could, in effect, form task organizations, it somewhat resembled the larger infantry regiment, which could employ battalion combat teams. According to Lieutenant Heinl, in terms of "strength and variety of material, the defense battalion ;might well be a regiment. Actually, the seacoast and antiaircraft artillery groups are almost small battalions, while the other three separate batteries (searchlight and sound locator and the two machine gun units) are undeniable batteries in the accepted sense of the word. The proposed 850 man infantry battalions would forestall any possible need to detail infantrymen from the regiments to reinforce the defense battalions. Consequently, Secretary of the Navy Frank Knox approved the creation of separate infantry battalions to serve with the defense battalions. After the Japanese attack on Pearl Harbor, the regiments and divisions -- and for a time the specialized units such as the raiders -- demanded a lion's share of manpower, and with few exceptions, the defense battalions had to fend for themselves without the planned infantry battalions, though occasionally with an organic rifle company. Every Marine in a typical defense battalion had to train to fight as an infantryman in an emergency, with the members of gun and searchlight crews leaving their usual battle stations. Rifle companies served at various times with the 6th, 7th, and 51st Defense Battalions, and such a component was planned for the 52nd, but not assigned. Those battalions that included a company of infantry bore the title "composite".

    Improvements in equipment, a changing strategic situation, and deployment in areas that varied from desolate coral atolls to dense jungle ensured that no single table of equipment or organization could apply at all times to every defense battalion. Each of the organizations tended to be unique -- one of a kind, as a battalion's history stated. Weapons and personnel reflected a unit's destination and duties, much as a child's erector set took the shape dictated by the person assembling the parts, or such was the view of James H. Powers, a veteran of the 8th Defense Battalion. The selection and assignment of men and equipment proved a dynamic process, as units moved about, split into detachments, underwent re-designation, and traded old equipment for new. Much of the weapons and material came from the stocks of the U.S. Army, which had similarly equipped coast and antiaircraft artillery units. The first 155 mm guns dated from World War I, but the Army quickly made modern types available, along with new 90 mm antiaircraft guns that replaced the 3 inch weapons initially used by the defense battalions. In addition, the Army provided both primitive sound-ranging equipment and three types of Signal Corps radar -- the early-model SCR268 and SCR270 and the more advanced SCR268, which provided automatic target tracking and gun-laying.

    By October 1941, the tables of organization for the new defense battalions had certain features in common, each calling for a headquarters battery, a sound-locator and searchlight battery, a 5 inch seacoast artillery group, a 3 inch antiaircraft group, and a machine-gun group. The specific allocation of personnel and equipment within each battalion depended, however, on where the battalion deployed and the changes prescribed by the Commandant from time to time. In brief, the defense battalions adhered to certain standard configurations, with individual variations due to time and circumstance. The average battalion strength during the war was 1,372 officers and men, including Navy medical personnel. Like manpower, the equipment used by the defense battalions also varied, although the armament of the typical wartime unit consisted of eight 155 mm guns, twelve 90 mm guns, nineteen 40 mm guns, twenty-eight 20 mm guns, and thirty-five .50 caliber heavy machine guns, supplemented in some instances by eight M3 light tanks.

    Beginning early in 1940, the defense battalions operated independently, or in concert with larger units, to secure strategic locations in the Atlantic and the Pacific. Colonel Harry K. Pickett's 3rd Defense Battalion undertook to support the current War Plan ORANGE by occupying Midway Island on 29 September 1940, setting up its weapons on two bleak, sandy spits described by one Marine as being inhabited by more than a million birds. Of the seven Marine defense battalions organized by late 1941, one stood guard in Iceland, five served in the Pacific -- including the 4th, posted briefly at Guantanamo Bay -- and another trained on the west coast for a westward deployment. The first Pacific-based defense battalions were nicknamed the RAINBOW Five" after the war plan in effect when the Japanese attacked Pearl Harbor. The five units were: the 7th in Samoa; the 6th, which took over from a detachment of the 3rd at Midway Island; the 3rd and 4th at Pearl Harbor, and the 1st divided among Pearl Harbor and Johnston, Palmyra, and Wake Islands. A sixth defense battalion, the 2nd, remained in training in California.

    The first real test of the base defense concept in the Pacific War began with savage air attacks against Wake Island on 8 December and lasted 15 days. Wake's defenders lacked radar and sound-ranging equipment, forcing the 400-man Marine garrison to rely on optical equipment to spot and identify the attacking aircraft, which inflicted heavy losses on the Americans during the first bombing raids. Commander Winfield S. Cunningham, who headed the Wake Island naval base, later insisted that one radar could have turned defeat into victory. In contrast, Technical Sergeant Charles A. Holmes, a fire-control specialist, believed that radar would never have affected the outcome of the situation . . . . The set, moreover, might have fallen into Japanese hands sufficiently intact to yield useful intelligence. While the Wake Island garrison fought against overwhelming numbers and ultimately had to yield, Japanese naval forces began a short lived harassment of Johnston and Palmyra that lasted until late December and stopped short of attempted landings. On 12 December, shells from a pair of submarines detonated a 12,000-gallon fuel storage tank on Johnston Island, but fire from 5-inch coast defense guns emplaced there forced the raiders to submerge. Similarly, a battery on Palmyra drove off a submarine that shelled the island on Christmas Eve.

    Elsewhere in the Pacific, Lieutenant Colonel Harold D. Shannon's 6th Defense Battalion strengthened the defenses of Midway where, by the spring of 1942, reinforcements arrived in the form of the antiaircraft group of the 3rd Defense Battalion, plus radar, light tanks, aircraft, infantrymen, and raiders. The Palmyra garrison was re-designated the 1st Marine Defense Battalion -- of which it had been a detachment before March 1942 -- under Lieutenant Colonel Bert A. Bone, with the detachment on Johnston Island reverting to control of the island commander.