Operation Roundup was the codename for a 1942 plan for an invasion of Northern France by Allied forces during World War II.
The plan, for an invasion in the spring of 1943, drawn up by Brigadier General Dwight D. Eisenhower, 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 (on the first day of the battle, the British Army lost almost 60,000 men) 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 Wehrmacht, the German forces, in the Mediterranean Sea instead (which he referred to as the "soft underbelly"), 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 Allied divisions 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.