Commerce raiding or guerre de course is a naval strategy of attacking an opponent's commercial shipping rather than contending for control of the seas with its naval forces. The objective is to make the war too expensive for the opponent to continue it.

Usually, commerce raiding is chosen by the weaker naval power who has little chance to succeed against the naval forces of its opponent.

Napoleonic Wars

During Britain's wars against revolutionary and Napoleonic France, the Royal Navy dominated the seas. France adopted a guerre de course strategy by licensing civilian privateers to seize British shipping.

American Civil War

During the American Civil War, the Confederacy operated a fleet of privateers and naval commerce raiders. The naval raiders include the CSS Sumter, CSS Alabama, and CSS Shenandoah.

World Wars Atlantic

During World War I and II, the First and Second Battle of the Atlantic saw Germany conducting a guerre de course against Britain and its allies mainly using submarines. However, Germany also used merchant raiders and warships to attack allied shipping — the geographical enclosed position of Germany and the strength of the Royal Navy, later aided by the United States Navy meant that it was difficult to deploy warships.

World War II Pacific

During World War II, the United States Navy used its submarines against Japanese shipping. The bulk of the Japanese merchant marine was sunk by American submarines. By the end of the war, Japan only had 12% of the tonnage of her pre-war shipping afloat.

See also

• Tonnage war
• Unrestricted submarine warfare
• Merchant raider
• German auxiliary cruiser Atlantis
• Q-ship