Battle of the Atlantic: How Warships and U-Boats Caused the Downfall of the German Fleet during World War II

The Battle of the Atlantic stands as the longest continuous military campaign of World War II, spanning from the first day of the war in September 1939 to Germany's surrender in May 1945. This maritime struggle would determine the fate of Britain and ultimately the outcome of the entire war, as control of the Atlantic shipping lanes became the decisive factor in whether the Allies could sustain their war effort against Nazi Germany. Winston Churchill would later write that the U-boat peril was the only thing that truly frightened him during the war, understanding that Britain's survival depended entirely on keeping the sea lanes open to North America.

The strategic importance of the Atlantic Ocean cannot be overstated in the context of World War II. Britain, despite its status as a global empire, was fundamentally dependent on imports for survival. The island nation produced only enough food to feed one-third of its population and relied on imports for virtually all raw materials needed for war production. Oil, steel, aluminum, rubber, and countless other strategic materials had to cross the Atlantic from North America, making Britain's lifeline a 3,000-mile stretch of often hostile ocean that German forces were determined to sever.

Germany's strategy for winning the war centered on the concept of economic warfare through unrestricted submarine attacks on Allied shipping. Admiral Karl Dönitz, commander of the German U-boat force, understood that Germany lacked the surface fleet to challenge British naval supremacy directly. Instead, he advocated for a campaign of commerce raiding that would strangle Britain's economy and force the island nation to sue for peace before American industrial capacity could tip the balance. Dönitz calculated that if his submarines could sink 700,000 tons of Allied shipping per month, Britain would be forced to surrender within a year.