Lably
Skip to content

Blockade

Prevention of trade or movement by force

  • 7 min read
  • 5 chapters
Nelson's Inshore Blockading Squadron at Cadiz, July 1797
Thomas Buttersworth · Public domain

Learn it on Lably

A blockading power can seek to cut off all maritime transport from and to the blockaded country, although stopping all land transport to and from an area may also be considered a blockade. Blockades restrict the trading rights of neutral parties, who must submit for inspection for contraband, which the blockading power may define narrowly or broadly, sometimes including food and medicine. In the 20th century, air power has also been used to enhance the effectiveness of blockades by halting air traffic within the blockaded airspace.

Close patrol of hostile ports, in order to prevent naval forces from putting to sea, is also referred to as a blockade. When coastal cities or fortresses were besieged from the landward side, the besiegers would often blockade the seaward side as well. Modern blockades have included cutting off electronic communications by jamming radio signals and severing undersea cables. Blockades often result in the starvation of the civilian population, notably during the blockade of Germany during World War I and the blockade of Biafra during the Nigerian Civil War.

History

Although primitive naval blockades have been in use for millennia, early attempts were limited by the time ships were able to stay at sea uninterruptedly. The first successful attempts at establishing a full naval blockade were made by the British Royal Navy during the Seven Years' War (1754–1763) against France. Following the 1759 British naval victory at Quiberon Bay, which ended any immediate threat of a major invasion of Britain, the British Royal Navy established a close blockade on the French coast. This starved French ports of commerce, weakening France's economy. Admiral Edward Hawke took command of the blockading fleet off Brest and extended the blockade to cover the entire French Atlantic coast from Dunkirk to Bordeaux, and to Marseille on France's Mediterranean coast.

During the North American operations of the Seven Years' War, the British Royal Navy blockaded the French on the other side of the Atlantic, specifically impeding access and supply to the colonies of New France on the St. Lawrence. Blockades contributed to the French loss of Canada in 1763.

The strategic importance of blockade became increasingly apparent during the French Revolutionary Wars of 1792 to 1802 and in the Napoleonic Wars of 1803 to 1815, when the Royal Navy successfully blockaded France, leading to major economic disruptions. The Union blockade of southern ports was a major factor in the American Civil War of 1861 to 1865.

During World War I (1914–1918), the Allies blockaded the Central Powers, depriving them of food-supplies and strategic materials. Germany's attempted U-boat blockade of Britain caused some shortages, but ultimately failed. A similar outcome followed in World War II (1939–1945).

Naval strategic thinkers, such as Sir Julian Corbett (1854–1922) and Alfred Thayer Mahan (1840–1914), wrote that naval conflicts were won primarily by decisive battles, but also by blockade.

Sign in to keep reading

4 more chapters are free with a Lably account.

More in War and military