Defence in depthDefence in depth (also known as deep defence or elastic defence) is a military strategy that seeks to delay rather than prevent the advance of an attacker, buying time and causing additional casualties by yielding space. Rather than defeating an attacker with a single, strong defensive line, defence in depth relies on the tendency of an attack to lose momentum over time or as it covers a larger area. A defender can thus yield lightly defended territory in an effort to stress an attacker's logistics or spread out a numerically superior attacking force.
BlockhouseA blockhouse is a small fortification, usually consisting of one or more rooms with loopholes, allowing its defenders to fire in various directions. It is usually an isolated fort in the form of a single building, serving as a defensive strong point against any enemy that does not possess siege equipment or, in modern times, artillery, air force and cruise missiles. A fortification intended to resist these weapons is more likely to qualify as a fortress or a redoubt, or in modern times, be an underground bunker.
Czechoslovak border fortificationsCzechoslovakia built a system of border fortifications as well as some fortified defensive lines inland, from 1935 to 1938 as a defensive countermeasure against the rising threat of Nazi Germany. The objective of the fortifications was to prevent the taking of key areas by an enemy—not only Germany but also Hungary and Poland—by means of a sudden attack before the mobilization of the Czechoslovak Army could be completed, and to enable effective defense until allies—Britain and France, and possibly the Soviet Union—could help.
BunkerA bunker is a defensive military fortification designed to protect people and valued materials from falling bombs, artillery, or other attacks. Bunkers are almost always underground, in contrast to blockhouses which are mostly above ground. They were used extensively in World War I, World War II, and the Cold War for weapons facilities, command and control centers, and storage facilities. Bunkers can also be used as protection from tornadoes. Trench bunkers are small concrete structures, partly dug into the ground.
FortificationA fortification is a military construction designed for the defense of territories in warfare, and is used to establish rule in a region during peacetime. The term is derived from Latin fortis ("strong") and facere ("to make"). From very early history to modern times, defensive walls have often been necessary for cities to survive in an ever-changing world of invasion and conquest. Some settlements in the Indus Valley Civilization were the first small cities to be fortified.
Maginot LineThe Maginot Line (Ligne Maginot, liɲ maʒino), named after the French Minister of War André Maginot, is a line of concrete fortifications, obstacles and weapon installations built by France in the 1930s to deter invasion by Germany and force them to move around the fortifications. The Maginot Line was impervious to most forms of attack. Consequently, the Germans invaded through the Low Countries in 1940, passing it to the north.
CasemateA casemate is a fortified gun emplacement or armored structure from which guns are fired, in a fortification, warship, or armoured fighting vehicle. When referring to antiquity, the term "casemate wall" means a double city wall with the space between the walls separated into chambers, which could be filled up to better withstand battering rams in case of siege (see Antiquity: casemate wall). In its original early modern meaning, the term referred to a vaulted chamber in a fort, which may have been used for storage, accommodation, or artillery which could fire through an opening or embrasure.
Atlantic WallThe Atlantic Wall (Atlantikwall) was an extensive system of coastal defences and fortifications built by Nazi Germany between 1942 and 1944 along the coast of continental Europe and Scandinavia as a defence against an anticipated Allied invasion of Nazi-occupied Europe from the United Kingdom, during World War II. The manning and operation of the Atlantic Wall was administratively overseen by the German Army, with some support from Luftwaffe ground forces.
FlamethrowerA flamethrower is a ranged incendiary device designed to project a controllable jet of fire. First deployed by the Byzantine Empire in the 7th century AD, flamethrowers saw use in modern times during World War I, and more widely in World War II as a tactical weapon against fortifications. Most military flamethrowers use liquid fuel, typically either gasoline or diesel, but commercial flamethrowers are generally blowtorches using gaseous fuels such as propane; gases are safer in peacetime applications, because their flames have less mass flow rate and dissipate faster, and often are easier to extinguish when necessary.
Battle of Iwo JimaThe Battle of Iwo Jima (19 February – 26 March 1945) was a major battle in which the United States Marine Corps (USMC) and United States Navy (USN) landed on and eventually captured the island of Iwo Jima from the Imperial Japanese Army (IJA) during World War II. The American invasion, designated Operation Detachment, had the purpose of capturing the island with its two airfields: South Field and Central Field. The Japanese Army positions on the island were heavily fortified, with a dense network of bunkers, hidden artillery positions, and of tunnels.
