Amphibious warfare is a type of offensive military operation that today uses naval ships to project ground and air power onto a hostile or hostile shore at a designated landing beach. Through history the operations were conducted using ship's boats as the primary method of delivering troops to shore. Since the Gallipoli Campaign, specialised watercraft were designed for landing troops and vehicles, including by landing craft and for insertion of commandos, by fast patrol boats and from mini-submersibles; the term amphibious first emerged in the UK and the USA during the 1930s with introduction of vehicles such as Vickers-Carden-Loyd Light Amphibious Tank or the Landing Vehicle Tracked. Amphibious warfare includes operations defined by their type, purpose and means of execution. In the British Empire at the time these were called combined operations which were defined as "...operations where naval, military or air forces in any combination are co-operating with each other, working independently under their respective commanders, but with a common strategic object."
All armed forces that employ troops with special training and equipment for conducting landings from naval vessels to shore agree to this definition. Since the 20th century an amphibious landing of troops on a beachhead is acknowledged as the most complex of all military maneuvers; the undertaking requires an intricate coordination of numerous military specialties, including air power, naval gunfire, naval transport, logistical planning, specialized equipment, land warfare and extensive training in the nuances of this maneuver for all personnel involved. An amphibious operation is similar to but in many ways different from land and air operations. At its basic, such operations include phases of strategic planning and preparation, operational transit to the intended theatre of operations, pre-landing rehearsal and disembarkation, troop landings, beachhead consolidation and conducting inland ground and air operations. Within the scope of these phases a vital part of success was based on the military logistics, naval gunfire and close air support.
Another factor is the variety and quantity of specialised vehicles and equipment used by the landing force that are designed for the specific needs of this type of operation. Amphibious operations can be classified as tactical or operational raids such as the Dieppe Raid, operational landings in support of a larger land strategy such as the Kerch–Eltigen Operation, a strategic opening of a new Theatre of Operations, for example the Operation Avalanche; the purpose of amphibious operations is always limited by the plan and terrain. Landings on islands less than 5,000 km2 in size are tactical with the limited objectives of neutralising enemy defenders and obtaining a new base of operation; such an operation may be prepared and planned in days or weeks, would employ a naval task force to land less than a division of troops. The intent of operational landings is to exploit the shore as a vulnerability in the enemy's overall position, forcing redeployment of forces, premature use of reserves, aiding a larger allied offensive effort elsewhere.
Such an operation requiring weeks to months of preparation and planning, would use multiple task forces, or a naval fleet to land corps-size forces, including on large islands, for example Operation Chromite. A strategic landing operation requires a major commitment of forces to invade a national territory in the archipelagic, such as the Battle of Leyte, or continental, such as Operation Neptune; such an operation may require multiple naval and air fleets to support the landings, extensive intelligence gathering and planning of over a year. Although most amphibious operations are thought of as beach landings, they can take exploit available shore infrastructure to land troops directly into an urban environment if unopposed. In this case non-specialised ships can offload troops and cargo using organic or facility wharf-side equipment. Tactical landings in the past have utilised small boats, small craft, small ships and civilian vessels converted for the mission to deliver troops to the water's edge.
Preparation and planning the naval landing operation requires the assembly of vessels with sufficient capacity to lift necessary troops employing combat loading. The military intelligence services produce a briefing on the expected opponent which guides the organisation and equipping of the embarked force. First specially designed landing craft were used for the Gallipoli landings, armoured tracked vehicles were available for the Guadalcanal Campaign. Helicopters were first used to support beach landings during Operation Musketeer. Hovercraft have been in use for naval landings by military forces since the 1960s. Recorded amphibious warfare goes back to ancient times; the Sea Peoples menaced the Egyptians from the reign of Akhenaten as captured on the reliefs at Medinet Habu and Karnak. The Hellenic city states resorted to opposed assaults upon each other's shores, which they reflected upon in their plays and other expressions of art; the landing at Marathon by the ancient Persians on 9 September 490 BC, was the largest amphibious until eclipsed by the landings at Battle of Gallipoli.
In 1565, the island of Malta was invaded by the Ottoman Turks during the Great Siege of Malta, forcing its defenders to retreat to the fortified cities. A strategic choke point in the Mediterranean Sea, its loss would have been so menacing for the Western European kingdoms that forces were urgently raised in order to relieve the island, but it took four months to train and move a 5,500-man amphibious force to lift the siege. Philip II, King of Spain de
A charge is a maneuver in battle in which combatants advance towards their enemy at their best speed in an attempt to engage in close combat. The charge is the dominant shock attack and has been the key tactic and decisive moment of many battles throughout history. Modern charges involve small groups against individual positions instead of large groups of combatants charging another group or a fortified line, it may be assumed that the charge was practiced in prehistoric warfare, but clear evidence only comes with literate societies. The tactics of the classical Greek phalanx included an ordered approach march, with a final charge to contact. In response to the introduction of firearms and Scottish troops at the end of the 16th century developed a tactic that combined a volley of musketry with a rapid close to close combat using swords. Successful, it was countered by effective discipline and the development of defensive bayonet tactics; the development of the bayonet in the late 17th century led to the bayonet charge becoming the main infantry charge tactic through the 19th century and into the 20th.
As early as the 19th century, tactical scholars were noting that most bayonet charges did not result in close combat. Instead, one side fled before actual bayonet fighting ensued; the act of fixing bayonets has been held to be connected to morale, the making of a clear signal to friend and foe of a willingness to kill at close quarters. The shock value of a charge attack has been exploited in cavalry tactics, both of armored knights and lighter mounted troops of both earlier and eras. Historians such as John Keegan have shown that when prepared against and by standing firm in face of the onslaught, cavalry charges failed against infantry, with horses refusing to gallop into the dense mass of enemies, or the charging unit itself breaking up. However, when cavalry charges succeeded, it was due to the defending formation breaking up and scattering, to be hunted down by the enemy, it must be noted, that while it was not recommended for a cavalry charge to continue against unbroken infantry, charges were still a viable danger to heavy infantry.
Parthian lancers were noted to require dense formations of Roman legionaries to stop, Frankish knights were reported to be harder to stop, if the writing of Anna Komnene is to be believed. However, only trained horses would voluntarily charge dense, unbroken enemy formations directly, in order to be effective, a strong formation would have to be kept – such strong formations being the result of efficient training. Heavy cavalry lacking a single part of this combination – composed of high morale, excellent training, quality equipment, individual prowess, collective discipline of both the warrior and the mount – would suffer in a charge against unbroken heavy infantry, only the best heavy cavalrymen throughout history would own these in regards to their era and terrain; the cavalry charge was a significant tactic in the Middle Ages. Although cavalry had charged before, a combination of the adoption of a frame saddle secured in place by a breast-band and the technique of couching the lance under the arm delivered a hitherto unachievable ability to utilise the momentum of the horse and rider.
These developments began in the 7th century but were not combined to full effect until the 11th century. The Battle of Dyrrhachium was an early instance of the familiar medieval cavalry charge. By the time of the First Crusade in the 1090s, the cavalry charge was being employed by European armies. However, from the dawn of the Hundred Years' War onward, the use of professional pikemen and longbowmen with high morale and functional tactics meant that a knight would have to be cautious in a cavalry charge. Men wielding either pike or halberd in formation, with high morale, could stave off all but the best cavalry charges, whilst English longbowmen could unleash a torrent of arrows capable of wreaking havoc, though not a massacre, upon the heads of heavy infantry and cavalry in unsuitable terrain, it became common for knights to dismount and fight as elite heavy infantry, although some continued to stay mounted throughout combat. The use of cavalry for flanking manoeuvres became more useful, although some interpretations of the knightly ideal led to reckless, undisciplined charges.
Cavalry could still charge dense heavy infantry formations head-on if the cavalrymen had a combination of certain traits. They had a high chance of success if they were in a formation, collectively disciplined skilled, equipped with the best arms and armour, as well as mounted upon horses trained to endure the physical and mental stresses of such charges. However, the majority of cavalry personnel lacked at least one of these traits discipline and horses trained for head-on charges. Thus, the use of the head-on cavalry charge declined, although Polish hussars, French Cuirassiers, Spanish and Portuguese conquistadores were still capable of succeeding in such charges due to their possession of the mentioned combination of the traits required for success in such endeavours. In the twentieth century, the cavalry charge was used, though it enjoyed sporadic and occasional success. In what was called the "last true cavalry charge", elements of the 7th Cavalry Regiment of the United States attacked Villista forces in the Battle of Guerrero on 29 March 1916.
The battle was a victory for the Americans, occurring in desert terrain
Medieval warfare is the European warfare of the Middle Ages. Technological and social developments had forced a dramatic transformation in the character of warfare from antiquity, changing military tactics and the role of cavalry and artillery. In terms of fortification, the Middle Ages saw the emergence of the castle in Europe, which spread to Western Asia. Publius Flavius Vegetius Renatus wrote De re militari in the late 4th century. Described by historian Walter Goffart as "the bible of warfare throughout the Middle Ages", De re militari was distributed through the Latin West. While Western Europe relied on a single text for the basis of its military knowledge, the Byzantine Empire in Southeastern Europe had a succession of military writers. Though Vegetius had no military experience and De re militari was derived from the works of Cato and Frontinus, his books were the standard for military discourse in Western Europe from their production until the 16th century. De re militari was divided into five books: who should be a soldier and the skills they needed to learn, the composition and structure of an army, field tactics, how to conduct and withstand sieges, the role of the navy.
According to Vegetius, infantry was the most important element of an army because it was cheap compared to cavalry and could be deployed on any terrain. One of the tenets he put forward was that a general should only engage in battle when he was sure of victory or had no other choice; as archaeologist Robert Liddiard explains, "Pitched battles in the eleventh and twelfth centuries, were rare."Although his work was reproduced, over 200 copies and extracts survive today, the extent to which Vegetius affected the actual practice of warfare as opposed to its concept is unclear because of his habit of stating the obvious. Historian Michael Clanchy noted "the medieval axiom that laymen are illiterate and its converse that clergy are literate", so it may be the case that few soldiers read Vegetius' work. While their Roman predecessors were well-educated and had been experienced in warfare, the European nobility of the early Medieval period were not renowned for their education, but from the 12th century, it became more common for them to read.
Some soldiers regarded the experience of warfare as more valuable than reading about it. While it is uncertain to what extent his work was read by the warrior class as opposed to the clergy, Vegetius remained prominent in the literature on warfare in the medieval period. In 1489, King Henry VII of England commissioned the translation of De re militari into English, "so every gentleman born to arms and all manner of men of war, soldiers and all others would know how they ought to behave in the feats of wars and battles". In Europe, breakdowns in centralized power led to the rise of a number of groups that turned to large-scale pillage as a source of income. Most notably the Vikings raided significantly; as these groups were small and needed to move building fortifications was a good way to provide refuge and protection for the people and the wealth in the region. These fortifications evolved over the course of the Middle Ages, the most important form being the castle, a structure which has become synonymous with the Medieval era in the popular eye.
The castle served as a protected place for the local elites. Inside a castle they were protected from bands of raiders and could send mounted warriors to drive the enemy from the area, or to disrupt the efforts of larger armies to supply themselves in the region by gaining local superiority over foraging parties that would be impossible against the whole enemy host. Fortifications were a important part of warfare because they provided safety to the lord, his family, his servants, they provided refuge from armies too large to face in open battle. The ability of the heavy cavalry to dominate a battle on an open field was useless against fortifications. Building siege engines was a time-consuming process, could be done without preparations before the campaign. Many sieges could take months, if not years, to demoralize the defenders sufficiently. Fortifications were an excellent means of ensuring that the elite could not be dislodged from their lands – as Count Baldwin of Hainaut commented in 1184 on seeing enemy troops ravage his lands from the safety of his castle, "they can't take the land with them".
In the Medieval period besieging armies used a wide variety of siege engines including: scaling ladders. Siege techniques included mining in which tunnels were dug under a section of the wall and rapidly collapsed to destabilize the wall's foundation. Another technique was to bore into the enemy walls, however this was not nearly as effective as other methods due to the thickness of castle walls. Advances in the prosecution of sieges encouraged the development of a variety of defensive counter-measures. In particular, Medieval fortifications became progressively stronger – for example, the advent of the concentric castle from the period of the Crusades – and more dangerous to attackers – witness the increasing use of machicolations, as well the preparation of hot or incendiary substances. Arrow slits, concealed doors for sallies, deep water wells were integral to resisting siege at this time. Designers of castles paid particular attention to defending entrances, protec
A siege is a military blockade of a city, or fortress, with the intent of conquering by attrition, or a well-prepared assault. This derives from Latin: sedere, lit.'to sit'. Siege warfare is a form of constant, low-intensity conflict characterized by one party holding a strong, defensive position. An opportunity for negotiation between combatants is not uncommon, as proximity and fluctuating advantage can encourage diplomacy; the art of conducting and resisting sieges is called siegecraft, or poliorcetics. A siege occurs when an attacker encounters a city or fortress that cannot be taken by a quick assault, which refuses to surrender. Sieges involve surrounding the target to block the provision of supplies and the reinforcement or escape of troops; this is coupled with attempts to reduce the fortifications by means of siege engines, artillery bombardment, mining, or the use of deception or treachery to bypass defenses. Failing a military outcome, sieges can be decided by starvation, thirst, or disease, which can afflict either the attacker or defender.
This form of siege, can take many months or years, depending upon the size of the stores of food the fortified position holds. The attacking force can circumvallate the besieged place, to build a line of earth-works, consisting of a rampart and trench, surrounding it. During the process of circumvallation, the attacking force can be set upon by another force, an ally of the besieged place, due to the lengthy amount of time required to force it to capitulate. A defensive ring of forts outside the ring of circumvallated forts, called contravallation, is sometimes used to defend the attackers from outside. Ancient cities in the Middle East show archaeological evidence of having had fortified city walls. During the Warring States era of ancient China, there is both textual and archaeological evidence of prolonged sieges and siege machinery used against the defenders of city walls. Siege machinery was a tradition of the ancient Greco-Roman world. During the Renaissance and the early modern period, siege warfare dominated the conduct of war in Europe.
Leonardo da Vinci gained as much of his renown from the design of fortifications as from his artwork. Medieval campaigns were designed around a succession of sieges. In the Napoleonic era, increasing use of more powerful cannon reduced the value of fortifications. In the 20th century, the significance of the classical siege declined. With the advent of mobile warfare, a single fortified stronghold is no longer as decisive as it once was. While traditional sieges do still occur, they are not as common as they once were due to changes in modes of battle, principally the ease by which huge volumes of destructive power can be directed onto a static target. Modern sieges are more the result of smaller hostage, militant, or extreme resisting arrest situations; the Assyrians deployed large labour forces to build new palaces and defensive walls. Some settlements in the Indus Valley Civilization were fortified. By about 3500 BC, hundreds of small farming villages dotted the Indus River floodplain. Many of these settlements had planned streets.
The stone and mud brick houses of Kot Diji were clustered behind massive stone flood dikes and defensive walls, for neighbouring communities quarrelled about the control of prime agricultural land. Mundigak in present-day south-east Afghanistan has defensive walls and square bastions of sun-dried bricks. City walls and fortifications were essential for the defence of the first cities in the ancient Near East; the walls were built of mudbricks, wood, or a combination of these materials, depending on local availability. They may have served the dual purpose of showing presumptive enemies the might of the kingdom; the great walls surrounding the Sumerian city of Uruk gained a widespread reputation. The walls were 9.5 km in length, up to 12 m in height. The walls of Babylon, reinforced by towers and ditches, gained a similar reputation. In Anatolia, the Hittites built massive stone walls around their cities atop hillsides, taking advantage of the terrain. In Shang Dynasty China, at the site of Ao, large walls were erected in the 15th century BC that had dimensions of 20 m in width at the base and enclosed an area of some 2,100 yards squared.
The ancient Chinese capital for the State of Zhao, founded in 386 BC had walls that were 20 m wide at the base. The cities of the Indus Valley Civilization showed less effort in constructing defences, as did the Minoan civilization on Crete; these civilizations relied more on the defence of their outer borders or sea shores. Unlike the ancient Minoan civilization, the Mycenaean Greeks emphasized the need for fortifications alongside natural defences of mountainous terrain, such as the massive Cyclopean walls built at Mycenae and other adjacent Late Bronze Age centers of central and southern Greece. Although there are depictions of sieges from the ancient Near East in historical sources and in art, there are few examples of siege systems that have been found archaeologically. Of the few examples, several are noteworthy: The late 9th-century BC siege system surrounding Tell es-Safi/Gath, consists of a 2.5 km long siege trench and other elements, is the earliest evidence of a circumvallation system known in the world.
It was built by Hazael of Aram Damascus, as part of his siege and conquest of Philistine Gath in the late 9th century BC (mentio
Mountain warfare refers to warfare in the mountains or rough terrain. This type of warfare is called Alpine warfare, after the Alps mountains. Mountain warfare is one of the most dangerous types of combat as it involves surviving not only combat with the enemy but the extreme weather and dangerous terrain. Mountain ranges are of strategic importance since they act as a natural border, may be the origin of a water source. Attacking a prepared enemy position in mountain terrain requires a greater ratio of attacking soldiers to defending soldiers than a war conducted on level ground. Mountains at any time of year are dangerous – lightning, strong gusts of wind, rock falls, snow pack, extreme cold, glaciers with their crevasses and the general uneven terrain and the slow pace of troop and material movement are all additional threats to combatants. Movement and medical evacuation up and down steep slopes and areas where pack animals cannot reach involves an enormous exertion of energy; the term mountain warfare is said to have come about in the Middle Ages after the monarchies of Europe found it difficult to fight the Swiss armies in the Alps because the Swiss were able to fight in smaller units and took vantage points against a huge unmaneuverable army.
Similar styles of attack and defence were employed by guerrillas and irregulars who hid in the mountains after an attack, making it challenging for an army of regulars to fight back. In Bonaparte's Italian campaign, the 1809 rebellion in Tyrol, mountain warfare played a large role. Another example of mountain warfare was the Crossing of the Andes carried out by the Argentinean Army of the Andes commanded by Gen José de San Martín in 1817. One of the divisions surpassed 5000 m in height. Mountain warfare came to the fore once again during World War I, when some of the nations involved in the war had mountain divisions that had hitherto not been tested; the Austro-Hungarian defence repelled Italian attacks as they took advantage of the mountainous terrain in the Julian Alps and the Dolomites, where frostbite and avalanches proved deadlier than bullets. During the summer of 1918, the Battle of San Matteo took place on the Italian front. In December 1914, another offensive was launched by the Turkish supreme commander Enver Pasha with 95,000–190,000 troops against the Russians in the Caucasus.
Insisting on a frontal attack against Russian positions in the mountains in the heart of winter, the end result was devastating and Enver lost 86% of his forces. The Italian Campaign in World War II, Siachen conflict were large-scale mountain warfare examples. Battles of Narvik Kokoda Track campaign Operation Rentier Operation Gauntlet Since the Partition of India in 1947, India and Pakistan have been in conflict over the Kashmir region, they have fought numerous additional skirmishes / border conflicts in the region. Kashmir is located in the highest mountain range in the world; the first hostilities between the two nations, in the Indo-Pakistani War of 1947, showed that both were ill-equipped to fight in biting cold, let alone at the highest altitudes in the world. During the Sino-Indian War of 1962, hostilities broke out between China in the same area; the subsequent Indo-Pakistani War of 1965 between India and Pakistan was fought in Kashmir's valleys rather than the mountains themselves, although several mountain battles took place.
In the Kargil War Indian forces sought to flush out opponents. The proxy warfare in 1999 was the only modern war, fought on mountains. Following the Kargil War, the Indian Army implemented specialist training on artillery use in the mountains, where ballistic projectiles have different characteristics than at sea level. Most of the Falklands War took place on hills in semi-Arctic conditions on the Falkland Islands. However, during the opening stage of the war, there was military action on the bleak mountainous island of South Georgia, when a British expedition sought to eject occupying Argentine forces. South Georgia is a periantarctic island, the conflict took place during the southern winter, so Alpine conditions prevailed down to sea level; the operation was unusual, in that it combined aspects of long-range amphibious warfare, arctic warfare and mountain warfare. It involved special forces troops and helicopters. Throughout history but since 1979, many mountain warfare operations have taken place throughout Afghanistan.
Since the coalition invasion of Afghanistan in 2001 these have been in the eastern provinces of Kunar and Nuristan. Kunar and eastern Nuristan are strategic terrain; the area constitutes a major infiltration route into Afghanistan, insurgents can enter these provinces from any number of places along the Pakistani border to gain access to a vast network of river valleys. In this part of Afghanistan, the US military has adopted a hybrid style of mountain warfare incorporating counterinsurgency theory, in which the population is paramount as the center of gravity in the fight. In counterinsurgency and holding territory is less important than avoiding civilian casualties; the primary goal of counterinsurgency is to secure the backing of the populace and thereby legitimize the government rather than focus on militarily defeating the insurgents. Counterinsurgency doctrine has proved difficult to implement in Nuristan. In the sparsely populated mountain regions of Eastern Afghanistan, strategists have argued for holding the high ground—a
Area denial weapon
An area denial weapon or Anti Access/Area Denial weapon system is a device or a strategy used to prevent an adversary from occupying or traversing an area of land, sea or air. The specific method used does not have to be effective in preventing passage as long as it is sufficient to restrict, slow down, or endanger the opponent; some area denial weapons pose long-lasting risks to anyone entering the area to civilians, thus are controversial. In medieval warfare and sturdy stakes were buried at the bottom of long lines of ditches, pointed end up diagonally, in order to prevent cavalry charges in a given area. If the stakes were spotted, soldiers would be forced to dismount and give up their advantage as cavalry as well as becoming easier targets; the correct layout of these extensive lines of ditches and the quality control of stake size and placement was part of the craft of war. A more modern version, allowing quicker dispersal and providing the advantage of being hidden more are caltrops, though items bearing close similarity had been in use for most of antiquity.
Many variants were used, such as boards with metal hooks, as described during battles of Julius Caesar. Passive fortification—ditches and obstacles such as dragon's teeth and Czech hedgehogs—were used as anti-tank measures during World War II. Simple rows or clusters of sharpened sticks, the use of small caltrops have been a feature of anti-infantry warfare since antiquity. However, due to the difficulty of mass-producing them in the pre-modern age, they were used except in the defense of limited areas or chokepoints during sieges, where they were used to help seal breaches. Increasing ease of production still did not prevent these methods from falling out of favor from the late Middle Ages onward. Caltrops are still sometimes used in modern conflicts, such as during the Korean War, where Chinese troops wearing only light shoes, were vulnerable. In modern times, special caltrops are sometimes used against wheeled vehicles with pneumatic tires; some South American urban guerrillas such as the Tupamaros and Montoneros, who called them "miguelitos," have used caltrops to avoid pursuit after ambushes.
The most common planted by hand or dispersed by artillery. Some modern prototypes experiment with automatic guns or artillery-delivered ammunitions that are fired only after remote sensing detects enemies. Booby traps or improvised explosive devices in sufficient concentration qualify as area denial weapons, though they are much easier to clear and pose less long-term danger. During an armed conflict there are several methods of countering land mines; these include using armoured vehicles to negate the effects of anti-personnel land mines. Land mines can be cleared either by hand, or by using specialised equipment such as tanks equipped with flails. Explosives can be used to clear mine fields, either by artillery bombardment, or with specialised charges such as Bangalore torpedoes, the Antipersonnel Obstacle Breaching System and the Python Minefield Breaching System. 156 states are parties to the Ottawa Treaty under which they have agreed not to use, produce or transfer anti-personnel mines. Anti-ship missiles are a modern method of stopping a potential adversary from attacking by sea.
China, North Korea and Iran all have developed or imported such weapons in an effort to develop a modern anti-access or A2/AD strategy to counter modern United States weaponry. In response to China’s pursuit of such A2/AD capabilities, the United States has developed the AirSea Battle doctrine. Amitai Etzioni of the Institute for Communitarian Policy Studies has suggested that AirSea Battle is an escalatory military posture that entails restructuring United States military forces and ordering additional weapons systems, that AirSea Battle could “lead to an arms race with China, which could culminate in a nuclear war.”Other methods of area denial at a strategic level include aircraft carriers, surface-to-air missiles, ballistic missiles, cruise missiles, electronic warfare and interceptor aircraft. Various CBRNE weapons can be used for area denial, as long. Fallout from nuclear weapons might be used in such a role. While never employed in this form, its use had been suggested by Douglas MacArthur during the Korean War.
Anthrax spores can contaminate the ground for long periods of time, thus providing a form of area denial. However, the short-term effects are to be low - the psychological effects on an opponent would be more significant; the massive use of defoliants such as Agent Orange can be used as an interdiction measure because they leave areas empty of any form of vegetation cover. In the desert-like terrain that ensues, it is impossible for the enemy to travel without being seen, there is little cover in case of an attack from the air. Many chemical weapons produce toxic effects on any personnel in an affected area. However, this has no tactical value, as the effects of indirect exposure do not develop fast or enough - though again, the psychological effect upon an enemy aware of the chemical usage may be considerable. There are however some chemical agents that are by design non-degrading, such as the nerve agent VX. Sulfur mustard was extensively used by both German and allied forces on the west front in World War I as an effective area-denial weapon through contaminating large land stripes by extensive shelling with HD/Gelbkreuz ordnance