Overseen by Brigadier General Dwight D. Eisenhower, the plan was developed in 1942 and reflected American enthusiasm for an early entry into Europe. Senior British commanders and politicians were reluctant to commit themselves to the invasion plan; mindful of the painful losses during the Battle of the Somme and the Battle of Passchendaele in the First World War, they preferred to avoid a direct assault on a powerful enemy. Winston Churchill, the Prime Minister of the United Kingdom, preferred a strategy of attacking the Wehrmacht, the German forces, in the Mediterranean Sea instead, and other British military leaders hoped to defer an invasion until the Germans had been worn down by fighting on the Eastern Front against the Russian Army. Churchill's plan would allow relatively inexperienced American forces to gain experience in a less risky theatre of war while they gradually built up overwhelming force before they engaged Germany head on. Given shortages of merchant shipping, landing craft, and other resources, the Roundup plan was considered to be unrealistic; it called for a force consisting of 48 Allieddivisions and 5,800 aircraft, with a landing on broad beachheads between the French ports of Boulogne and Le Havre. By comparison, the eventual Normandy landings, which occurred over a year later in June 1944, and the subsequent campaign, featured only 39 Allied divisions. After Churchill pressed for a landing in French North Africa in 1942, General George Marshall, the U.S. Army Chief of Staff, suggested instead to U.S. President Franklin Roosevelt that the United States abandon the Germany-first strategy and take the offensive in the Pacific War. Roosevelt "disapproved" the proposal, saying it would do nothing to help the Soviet Union. Instead, with Roosevelt's support and Marshall unable to persuade the British to change their minds, the decision was made at the Second Claridge Conference in late July 1942 to carry out Operation Torch, the Allied invasion of French North Africa. Most of the troops and supplies accumulated for Roundup were used to implement Torch with preparations for Roundup given lower priority because of the uncertainties of Allied strategy. The British were as reluctant to abandon Roundup fully as they had been to support the plan. In November 1942 Eisenhower, now a lieutenant general, told Churchill that no major operation on the Continent could be carried out before 1944. Briefings concerning the plan brought Eisenhower’s organizational and diplomatic skills to the attention of senior civil and military leaders in the United States and Europe, launching his meteoric rise to Supreme Allied Commander in Europe. Operation Roundup included Operation Sledgehammer and the later variant, Operation Roundhammer. British Lieutenant General Frederick E. Morgan incorporated aspects of the plan into the earliest version of the plan that became Operation Overlord.
