High Quality Content by WIKIPEDIA articles! A blockade is an effort to cut off food, supplies, war material or communications from a particular area by force, either in part or totally. A blockade should not be confused with an embargo or sanctions, which are legal barriers to trade, and is distinct from a siege in that a blockade is usually directed at an entire country or region, rather than a fortress or city. Most blockades historically took place at sea, with the blockading power seeking 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. In the 20th century air power has also been used to enhance the effectiveness of the blockade by halting all air traffic within the blockaded air space.