It would be described as Battle of the Atlantic, in World War II, a contest between the Western Allies and the Axis powers (particularly Germany) for the control of Atlantic sea routes. For the Allied powers, the battle had three objectives: blockade of the Axis powers in Europe, security of Allied sea movements, and freedom to project military power across the seas.
The term "Battle of the Atlantic" was first coined by Winston Churchill in 1941. It refers generally to the series of clashes between armed Allied supply convoys and German U-boats in the Atlantic Ocean during World War II. The United States sent supplies to the Allied Powers from the beginning of the war in 1939. Problems arose when the Germans and their allies decided to use submarine warfare in an attempt to control the shipping lanes of the Atlantic Ocean. To address this, the Allies began putting convoys together to offer protection by safety in numbers and had these convoys protected by escorts of military vessels. The Allies were able to assert almost undisputed control over the Atlantic Ocean by 1943.
