Blockade of Strait of Hormuz and Major Naval Sieges in Modern History
Yasmeen Aboujabal, Alanoud Al-Thani
The Strait of Hormuz, a global energy artery, is effectively blocked after the U.S. and Iran imposed tit-for-tat bans. It is one of the most notable modern naval blockades, alongside historic sieges from Gaza to Biafra. The tactic of naval blockade, which cuts off an enemy's supplies without ground invasion, has a long and often devastating history.
The Strait of Hormuz, which once carried about one-fifth of the world's oil and gas, has been effectively closed after the United States and Iran imposed competing blockades. The situation revives the history of naval sieges, one of the oldest weapons of war—requiring no infantry or invasion, only the cutting off of an enemy's supplies.
Below are notable naval blockades in modern history, from Gaza to Germany in World War I.
Israel's blockade of Gaza (2007–present): One of the longest-running modern sieges, enforced by land, sea, and air. Israel restricts goods and essentials entering the Gaza Strip, home to 2.3 million people. Since 2008, many ships from the Freedom Flotilla movement have tried to break the blockade but have been intercepted or attacked. In April 2026, Israel raided 22 of the 58 vessels of the Global Sumud Flotilla in international waters more than 1,000 km from Gaza.
The Biafra blockade (1967–1970): During the Nigerian Civil War, the federal government imposed land, sea, and air blockades on the secessionist Republic of Biafra. Millions died from starvation and disease. The siege ended when Biafra surrendered in January 1970.
The Beira Patrol (1966–1975): The British Navy blockaded the port of Beira (Mozambique) to prevent oil from reaching Rhodesia (today's Zimbabwe) under United Nations sanctions. The strategic aim failed because Rhodesia still received oil via South Africa. The blockade ended in July 1975.
The "quarantine" of Cuba during the Cuban Missile Crisis (1962): The U.S. called it a "quarantine" rather than a blockade to avoid being seen as an act of war. U.S. warships intercepted Soviet vessels 500 nautical miles from Cuba. After 13 tense days, the Soviets agreed to dismantle the missiles in exchange for a U.S. pledge not to invade. The quarantine ended on November 20, 1962.
The Wonsan blockade (1951–1953): U.S.-led United Nations forces blockaded North Korea's Wonsan port during the Korean War, lasting 861 days. Initial minesweeping operations caused losses. The blockade forced North Korea and China to divert troops from the front line.
The submarine blockade of Japan (1942–1945): The U.S. used submarines to attack merchant ships and lay mines, cutting off Japan's supplies of oil, rubber, and food. About 1,300 Japanese merchant ships and 200 warships were sunk. By 1945, oil imports had nearly ceased entirely.
The blockade of the Eastern Mediterranean (1915–1918): The Allies (Britain, France, Italy) blockaded the eastern Mediterranean coast to cut off supplies to the Ottoman Empire. Drought and locust swarms worsened the food crisis, causing a famine that killed about 500,000 people. The blockade was lifted in October 1918.
The Allied blockade of Germany (1914–1919): The British Navy blockaded from the English Channel to Norway, cutting off Germany's access to the ocean. The result was the famine winter of 1916–1917, with an estimated 424,000–763,000 civilians dying from hunger-related diseases. The blockade was fully lifted only in July 1919 after the Treaty of Versailles was signed.
