A more thorough explanation:

A pacific blockade is a type of blockade that is established without a declaration of war. It is a belligerent's prevention of access to or egress from an enemy's ports by stationing ships to intercept vessels trying to enter or leave those ports. To be binding, a blockade must be effective, meaning it must be maintained by a force sufficient to prevent access to ports.

For example, during the American Civil War, the Union Navy established a pacific blockade of the Confederate ports along the Atlantic and Gulf coasts. This blockade prevented the Confederacy from exporting cotton and importing much-needed supplies, ultimately contributing to their defeat.

Another example is the British pacific blockade of Germany during World War I. This blockade prevented Germany from receiving essential supplies, leading to widespread hunger and contributing to the eventual surrender of Germany.

In summary, a pacific blockade is a type of blockade that can be established without a declaration of war. It is a powerful tool used by belligerents to prevent access to enemy ports and ultimately contribute to their defeat.