A naval blockade is a military strategy used to prevent ships from entering or leaving a specific area, usually a port or coastline. This tactic is often employed during conflicts to restrict the movement of goods, supplies, and reinforcements to an enemy. By controlling access to the sea, a nation can weaken its opponent's resources and capabilities. Naval blockades can be enforced by various naval forces, including those of countries like the United States or United Kingdom. They may involve the use of warships, submarines, and aircraft to monitor and intercept vessels. Blockades can be total, stopping all traffic, or selective, allowing certain ships to pass while restricting others.