However, in the longer term and in order to handle the large quantities of reinforcements and supplies needed for the campaign, quayside discharge of Liberty ships would be necessary.

[4] Seven ports in Normandy were expected to be captured and opened in the first four weeks after D-Day: Isigny-sur-Mer, Cherbourg, Grandcamp-Maisy, Saint-Vaast-sur-Seulles, Barfleur, Granville, Manche and Saint-Malo.

[6] However, all the ports were expected to have facilities destroyed, harbors blocked and approaches mined by the Germans, requiring extensive repairs before they could be used efficiently.

[11] Operation Chastity planned to construct floating piers in the pool, allowing large ships to tie up alongside, with causeways to carry cargo and troops to the shore.

As it offered the greatest potential to solve the Allies' logistical problems, it was given highest priority, and US Third Army was given the objective of capturing Brittany.

At this point, Wood proposed blocking the base of the Brittany peninsula at Angers rather than Quiberon, preparatory to moving his division eastward towards Chartres.

[27] On 4 August, Middleton ordered the division to secure a line along the Vilaine River from Rennes to the coast, particularly the bridges at Redon and La Roche-Bernard, but with forces oriented eastward.

However, the German commander, General der Artillerie Wilhelm Fahrmbacher, later stated that had the Americans attacked Lorient in force between 6 and 9 August, they would probably have succeeded.

[46] The wisdom of the decision to abandon Operation Chastity has been the subject of debate,[47] but the preceding failure to seize Quiberon Bay has been overlooked by many historians.

[42] Those who regard Operation Chastity as a missed opportunity state that if the port on Quiberon Bay had been established, it would have given the 12th Army Group a high-capacity supply base with direct rail lines to the east, solving their logistical problems.

[47] For example, Norman R. Denny of the U.S. Army Command and General Staff College stated that the logistics shortfalls that plagued the Allied campaign in Europe, due to the failure to implement Operation Chastity, "helped eliminate" the possibility of Germany surrendering in 1944.

[48] He further argued that the actions of Wood, Middleton, Patton, Lieutenant General Omar Bradley and Eisenhower made the advance into Brittany futile and endangered the Allied drive towards Germany.

[49] Similarly, Lieutenant Colonel Harold L. Mack, of the Communications Zone staff, described the failure to implement Operation Chastity as "the critical error of World War II".

[50] Mack places the blame for failing to capture Quiberon Bay primarily on Wood, who "had set his heart on participating in the main drive for Paris, where he could achieve fame and glory" and only half-heartedly carried out his orders, but accuses all Wood's superiors in the chain of command of failing to appreciate the "supreme need of taking Quiberon Bay".

[51] Patrick S. Williams argues that SHAEF gambled that devoting the bulk of US Third Army to outflanking the German force in the Falaise pocket would mean a decisive victory over Germany could be attained before lack of logistics stopped the Allied advance, that a larger force should have been devoted to seizing the Brittany ports and that the decision to cancel Operation Chastity exacerbated the strain on an already fragile Allied logistical system.

But the Allied High Command threw away the best chance of exploiting this great opportunity by sticking to the outdated pre-invasion programme, in which a westward move to capture Brittany ports was to be the next step.

[54] Martin van Creveld argues that although Patton and his subordinates "ignored plans" and "refused to be tied down by logisticians tables", their rapid eastwards advance threatened to cut off the German forces, causing them to rout out of France.

Additionally, the Allies possessed more motor transport than any other army and were operating in summer, over a good road network, without enemy air interdiction and amongst a friendly population.

[55] After the war, Wood stood by his attempt to turn his division east instead of taking Quiberon Bay and Lorient, stating, "We were forced to adhere to the original plan...