|
Operation Cobra was the codename for an offensive launched by the First United States Army seven weeks after the D-Day landings, during the Normandy Campaign of World War II. American Lieutenant General Omar Bradley's intention was to take advantage of the German preoccupation with British and Canadian activity around the town of Caen, in Operation Goodwood,〔Trew, p. 64〕 and immediately punch through the German defenses that were penning in his troops while the Germans were distracted and unbalanced. Once a corridor had been created, the First Army would then be able to advance into Brittany, rolling up the German flanks and releasing itself of the constraints imposed by operating in the Norman bocage countryside. After a slow start the offensive gathered momentum, and German resistance collapsed as scattered remnants of broken units fought to escape to the Seine. Lacking the resources to cope with the situation, the German response was ineffectual, and the entire Normandy front soon collapsed. Operation Cobra, together with concurrent offensives by the Second British and First Canadian Armies, was decisive in securing an Allied victory in the Normandy Campaign. Having been delayed several times by poor weather, Operation Cobra commenced on 25 July with a concentrated aerial bombardment from thousands of Allied aircraft. Supporting offensives had drawn the bulk of German armored reserves toward the British and Canadian sector, and coupled with the general lack of men and materiel available to the Germans, it was impossible for them to form successive lines of defense. Units of VII Corps led the initial two-division assault, while other First Army corps mounted supporting attacks designed to pin German units in place. Progress was slow on the first day, but opposition started to crumble once the defensive crust had been broken. By 27 July, most organized resistance had been overcome, and VII and VIII Corps were advancing rapidly, isolating the Cotentin peninsula. By 31 July, XIX Corps had destroyed the last forces opposing the First Army, and Bradley's troops were finally freed from the bocage. Reinforcements were moved west by Field Marshal Günther von Kluge and employed in various counterattacks, the largest of which (codenamed Operation ''Lüttich'') was launched on 7 August between Mortain and Avranches. Although this led to the bloodiest phase of the battle, it was mounted by already exhausted and understrength units, and had little effect other than to further deplete von Kluge's forces. On 8 August, troops of the newly activated Third United States Army captured the city of Le Mans, formerly the German Seventh Army's headquarters. Operation Cobra transformed the high-intensity infantry combat of Normandy into rapid maneuver warfare, and led to the creation of the Falaise pocket and the loss of the German position in northwestern France. ==Background== Following the successful Allied invasion of Normandy on 6 June 1944, progress inland was slow. To facilitate the Allied build-up in France and to secure room for further expansion, the deep water port of Cherbourg on the western flank of the American sector and the historic town of Caen in the British and Canadian sector to the east, were early objectives.〔Van der Vat, p. 110〕 The original plan for the Normandy campaign envisioned strong offensive efforts in both sectors, in which the Second Army (Lieutenant-General Sir Miles Dempsey) would secure Caen and the area south of it and the First US Army (Lieutenant General Omar Bradley) would "wheel round" to the Loire.〔Bradley, p. 261〕〔Williams, p. 24〕 General Sir Bernard Montgomery—commanding all Allied ground forces in Normandy—intended Caen to be taken on D-Day, while Cherbourg was expected to fall 15 days later.〔Williams, p. 38〕 The Second Army was to seize Caen and then form a front to the southeast, extending to Caumont-l'Éventé, to acquire airfields and protect the left flank of the First US Army as it moved on Cherbourg.〔Ellis, p. 78〕 Possession of Caen and its surroundings—desirable for open terrain that would permit maneuver warfare—would also give the Second Army a suitable staging area for a push south to capture Falaise, which could be used as the pivot for a swing right to advance on Argentan and then the Touques River.〔Greiss, p.308〕〔Ellis, p. 81〕 Caen's capture has been described by historian L. F. Ellis as the most important D-Day objective assigned to Lieutenant-General Crocker's British I Corps. Ellis and Chester Wilmot called the Allied plan "ambitious" since the Caen sector contained the strongest defences in Normandy.〔 The initial attempt by I Corps to reach the city on D-Day was blocked by elements of the 21st Panzer Division and with the Germans committing most of the reinforcements sent to meet the invasion to the defense of Caen, the Anglo-Canadian front rapidly congealed short of Second Army's objectives.〔Bercuson, p. 215〕 Operation Perch in the week following D-Day and Operation Epsom (26–30 June) brought some territorial gains and depleted its defenders but Caen remained in German hands until Operation Charnwood (7–9 July), when the Second Army managed to take the northern part of the city up to the River Orne in a frontal assault.〔Keegan, p. 135〕〔Williams, p. 131〕 The successive Anglo-Canadian offensives around Caen kept the best of the German forces in Normandy, including most of the available armor, to the eastern end of the Allied lodgement, but even so First US Army made slow progress against dogged German resistance.〔 In part, operations were slow due to the constraints of the bocage landscape of densely packed banked hedgerows, sunken lanes, and small woods, for which U.S. units had not trained.〔Greiss, p. 317〕 With no port facilities in Allied hands, all reinforcement and supply had to take place over the beaches via the two Mulberry harbors and was at the mercy of the weather.〔Greiss, p. 308–310〕 On 19 June, a severe storm descended on the English Channel, lasting for three days, and causing significant delays to the Allied build-up and the cancellation of some planned operations.〔Williams, p. 114〕 The First US Army advance in the western sector was eventually halted by Bradley before the town of Saint-Lô,〔Williams, p. 163〕 to concentrate on the seizure of Cherbourg.〔Greiss, p. 312〕 The defense of Cherbourg consisted largely of four battlegroups formed from the remnants of units that had retreated up the Cotentin peninsula but the port defences had been designed principally to meet an attack from the sea.〔Hastings, p. 163〕 Organized German resistance ended only on 27 June, when the 9th US Infantry Division managed to reduce the defences of Cap-de-la-Hague, north-west of the city.〔Hastings, p. 165〕 Within four days, VII Corps (Major General J. Lawton "Lightning Joe" Collins) resumed the offensive toward Saint-Lô, alongside XIX Corps and VIII Corps, causing the Germans to move additional armor into the U.S. sector.〔Greiss, p. 316〕〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Operation Cobra」の詳細全文を読む スポンサード リンク
|