Barbed wire in the context of Wire obstacle

The Western Front was one of the main theatres of war during World War I. Following the outbreak of war in August 1914, the German Army opened the Western Front by invading Luxembourg and Belgium, then gaining military control of important industrial regions in France. The German advance was halted with the Battle of the Marne. Following the Race to the Sea, both sides dug in along a meandering line of fortified trenches, stretching from the North Sea to the Swiss frontier with France, the position of which changed little except during early 1917 and again in 1918.

Between 1915 and 1917 there were several offensives along this front. The attacks employed massive artillery bombardments and massed infantry advances. Entrenchments, machine gun emplacements, barbed wire, and artillery repeatedly inflicted severe casualties during attacks and counter-attacks and no significant advances were made. Among the most costly of these offensives were the Battle of Verdun, in 1916, with a combined 700,000 casualties, the Battle of the Somme, also in 1916, with over a million casualties, and the Battle of Passchendaele, in 1917, with 487,000 casualties.

Trench warfare is a type of land warfare using occupied lines largely comprising military trenches, in which combatants are well-protected from the enemy's small arms fire and are substantially sheltered from artillery. It became archetypically associated with World War I (1914–1918), when the Race to the Sea rapidly expanded trench use on the Western Front starting in September 1914.

Trench warfare proliferated when a revolution in firepower was not matched by similar advances in mobility, resulting in a grueling form of warfare in which the defender held the advantage. On the Western Front in 1914–1918, both sides constructed elaborate trench, underground, and dugout systems opposing each other along a front, protected from assault by barbed wire. The area between opposing trench lines (known as "no man's land") was fully exposed to artillery fire from both sides. Attacks, even if successful, often sustained severe casualties.

During World War II, the United States forcibly relocated and incarcerated about 120,000 people of Japanese descent in ten concentration camps operated by the War Relocation Authority (WRA), mostly in the western interior of the country. About two-thirds were U.S. citizens. These actions were initiated by Executive Order 9066, issued by President Franklin D. Roosevelt on February 19, 1942, following Imperial Japan's attack on Pearl Harbor on December 7, 1941. About 127,000 Japanese Americans then lived in the continental U.S., of which about 112,000 lived on the West Coast. About 80,000 were Nisei ('second generation'; American-born Japanese with U.S. citizenship) and Sansei ('third generation', the children of Nisei). The rest were Issei ('first generation') immigrants born in Japan, who were ineligible for citizenship. In Hawaii, where more than 150,000 Japanese Americans comprised more than one-third of the territory's population, only 1,200 to 1,800 were incarcerated.

Internment was intended to mitigate a security risk which Japanese Americans were believed to pose. The scale of the incarceration in proportion to the size of the Japanese American population far surpassed similar measures undertaken against German and Italian Americans who numbered in the millions and of whom some thousands were interned, most of these non-citizens. Following the executive order, the entire West Coast was designated a military exclusion area, and all Japanese Americans living there were taken to assembly centers before being sent to concentration camps in California, Arizona, Wyoming, Colorado, Utah, Idaho, and Arkansas. Similar actions were taken against individuals of Japanese descent in Canada. Internees were prohibited from taking more than they could carry into the camps, and many were forced to sell some or all of their property, including their homes and businesses. At the camps, which were surrounded by barbed wire fences and patrolled by armed guards, internees often lived in overcrowded barracks with minimal furnishing.

The National Cowboy & Western Heritage Museum is a museum in Oklahoma City, Oklahoma, United States, with more than 28,000 Western and Native American art works and artifacts. The facility also has the world's most extensive collection of American rodeo photographs, barbed wire, saddlery, and early rodeo trophies. Museum collections focus on preserving and interpreting the heritage of the American West. The museum has an extensive collection of paintings by Charles Marion Russell and Frederic Remington. It also hosts the annual Prix de West Invitational Art Exhibition and Sale each June, one of the leading events in the world of Western American Art. The Prix de West Artists sell original works of art as a fundraiser for the museum.

British heavy tanks were a series of related armoured fighting vehicles developed by the UK during the First World War. The Mark I was the world's first tank, a tracked, armed, and armoured vehicle, to enter combat. The name "tank" was initially a code name to maintain secrecy and disguise its true purpose. The tank was developed in 1915 to break the stalemate of trench warfare. It could survive the machine gun and small-arms fire in "no man's land", travel over difficult terrain, crush barbed wire, and cross trenches to assault fortified enemy positions with powerful armament. Tanks also carried supplies and troops.

British heavy tanks are distinguished by a rhomboidal shape with a high climbing face of the track, designed to cross the wide and deep trenches prevalent on the battlefields of the Western Front. Due to the height necessary for this shape, an armed turret would have made the vehicle too tall and unstable. Instead, the main armament was arranged in sponsons at the side of the vehicle. The prototype, named "Mother", mounted a 6-pounder (57 mm) cannon and a Hotchkiss machine gun at each side. Later, subtypes were produced with machine guns only, which were designated "Female", while the original version with the protruding 6-pounder was called "Male".

Obstacle course racing (OCR) is a sport in which a competitor, traveling on foot, must overcome various physical challenges in the form of obstacles. Races vary in length from courses with obstacles close together to events of several kilometers which incorporate elements of track, road and/or cross country/trail running. Courses may include climbing over walls or up ropes, monkey bars, carrying heavy objects, traversing bodies of water or mud, crawling under barbed wire, and jumping through fire.Since the beginning of modern OCR with the Tough Guy Competition in 1987, the sport has grown in popularity such that more than 2500 events are held annually across the world and several run organizing companies are commercially successful.

The Inner German border (German: innerdeutsche Grenze or deutsch–deutsche Grenze; initially also Zonengrenze, "Zonal boundary") was the border between the German Democratic Republic (GDR or East Germany) and the Federal Republic of Germany (FRG or West Germany) from 1949 to 1990. It ran north-south in a 1,381 kilometres (858 mi) long, irregular L-shaped line from Dassow at the Baltic Sea to Eichigt at the border with Czechoslovakia. The better-known Berlin Wall was a physically separate, less elaborate, and much shorter border barrier surrounding West Berlin, more than 170 kilometres (110 mi) to the east of the Inner German border.

The Inner German border was formally established by the Potsdam Agreement on 1 August 1945 as the boundary between the Western and Soviet occupation zones in Allied-occupied Germany. On the Eastern side, it was made one of the world's most heavily fortified frontiers, defined by a continuous line of high metal fences and walls, barbed wire, alarms, anti-vehicle ditches, watchtowers, automatic booby traps and minefields. It was patrolled by 50,000 armed Border Troops of the GDR who faced tens of thousands of West German, British and US guards and soldiers. In the hinterlands behind the border, more than a million NATO and Warsaw Pact troops awaited the possible outbreak of World War III in Europe. It was a physical manifestation of Winston Churchill's metaphorical Iron Curtain that separated the Soviet and Western blocs during the Cold War. Built by the East German government in phases from 1952 to the late 1980s, the fortifications were constructed to stop Republikflucht, the large-scale emigration of East German citizens to the West, about 1,000 of whom are said to have died trying to cross it during its 45-year existence. It caused widespread economic and social disruption on both sides; East Germans living nearby suffered especially draconian restrictions.

A prison escape (also referred to as a bust out, breakout, jailbreak, jail escape or prison break) is the act of an inmate leaving prison through unofficial or illegal ways. Normally, when this occurs, an effort is made on the part of authorities to recapture them and return them to their original detainers. Escaping from prison is also a criminal offense in some countries, such as the United States and Canada, and usually results in time being added to the inmate's sentence, as well as the inmate being placed under increased security that is usually a maximum security prison or supermax prison. In Germany and a number of other countries, it is considered human nature to want to escape from a prison and it is considered as a violation of the right of freedom, so escape is not penalized in itself (in the absence of other factors such as threats of violence, actual violence, or property damage).

Many prisons use security features such as CCTV, perimeter sensors, barred windows, high walls, barbed wire, razor wire, and electric fencing to prevent escapes. Even natural geographic features can play significant roles in preventing escapes; historically, mountains and islands were chosen as ideal settings for prison construction, given their significance in creating territorial isolation from outside worlds.

During World War I, France was one of the Triple Entente powers allied against the Central Powers. Although fighting occurred worldwide, the bulk of the French Army's operations occurred in Belgium, Luxembourg, France and Alsace-Lorraine along what came to be known as the Western Front, which consisted mainly of trench warfare. Specific operational, tactical, and strategic decisions by the high command on both sides of the conflict led to shifts in organizational capacity, as the French Army tried to respond to day-to-day fighting and long-term strategic and operational agendas. In particular, many problems caused the French high command to re-evaluate standard procedures, revise its command structures, re-equip the army, and to develop different tactical approaches.