A blockade is an effort usually (but not always, see below) at sea, to prevent supplies from reaching the enemy.
Historical blockades include:
- Union blockade of the Confederacy
- United Kingdom blockade of Germany during World War I
- Battle of the Atlantic
- United States blockade of Japan during World War II
- United States blockade of Cuba during 1962 Cuban missile crisis
- Russian land blockade of West Berlin, 1948-1949; the response was the Berlin Airlift.