Anti-tank warfare
Anti-tank warfare refers to the military strategies, tactics, and weapon systems designed to counter and destroy enemy armored vehicles, particularly tanks. It originated during World War I following the first deployment of tanks in 1916, and has since become a fundamental component of land warfare doctrine. Over time, anti-tank warfare has evolved to include a wide range of systems, from handheld infantry weapons and anti-tank guns to guided missiles and air-delivered munitions.
File:Indian troops in North Africa parade with a Boys anti-tank rifle and 'Molotov cocktail' petrol bombs, 6 October 1940. E699.jpg|thumb| British Indian Army tank-hunting squad with anti-tank rifle and Molotov cocktails in North Africa, 6 October 1940
Anti-tank warfare evolved rapidly during World War II, leading to infantry-portable weapons.
File:The British Army in Italy 1944 NA18188.jpg|thumb|right| A British 17-pounder anti-tank gun towed behind half-track in Italy, 1 September 1944
Through the Cold War of 1947–1991, the United States, anti-tank weapons have also been upgraded in number and performance.
Since the end of the Cold War in 1992, new threats to tanks and other armored vehicles have included remotely detonated improvised explosive devices.
During the Russian invasion of Ukraine, drones and loitering munitions have attacked and destroyed tanks.
Tank threat
Anti-tank warfare evolved as a countermeasure to the threat of the tank's appearance on the battlefields of the Western Front of the First World War. The tank had been developed to negate the German system of trenches, and allow a return to maneuver against enemy's flanks and to attack the rear with cavalry.The use of the tank was mainly based on the assumption that, once they were able to eliminate the German trench lines with their machine gun and infantry support gun positions, the Allied infantry would follow and secure the breach, and the cavalry would exploit the breach in the trench lines by attacking into the depth of German-held territory, eventually capturing the field artillery positions and interdicting logistics and reserves being brought up from the rear areas. Naval crews initially used to operate the installed naval guns and machine guns were replaced with Army personnel who were more aware of the infantry tactics with which the tanks were intended to cooperate. However, there was no means of communication between the tank's crew and the accompanying infantry, or between the tanks participating in combat. Radios were not yet portable or robust enough to be mounted in a tank, although Morse Code transmitters were installed in some Mark IVs at Cambrai as messaging vehicles. Attaching a field telephone to the rear would become a practice only during the next war. With greater use of tanks by both sides it was realized that the accompanying infantry could be forced to ground by ambush fire, thus separating them from the tanks, which would continue to advance, eventually finding themselves exposed to close-assaults by German infantry and sappers.
The early tanks were mechanically rudimentary. The thick armor generally prevented penetration by small arms fire and shell fragments. However, even a near miss from field artillery or an impact from a mortar could easily disable or destroy the tank: if the fuel tank was ruptured, it could incinerate the tank's crew. A large caliber gun was recognized as a tactical necessity to attack machine gun positions and defeat any infantry field pieces found in the trench lines which could easily disable tank track with the HE ammunition. This was achieved by mounting a 57 mm QF 6 pounder Hotchkiss light naval gun in the hull barbettes. Hull and track engineering was largely dictated by the terrain—the need to cross wide trenches—although the relationship between ground pressure and soil-vehicle mechanics was not resolved until the Second World War. Turrets were later introduced on medium and light tanks to react to ambushes during the advance.
First World War
The tank, when it appeared on the Western Front in September 1916, was a surprise to German troops, but not the German General Staff. The French Army Staff was highly critical of the British Army's early fielding of the Mark I vehicles in small numbers because the French trials showed the armored vehicles to be highly unreliable. They judged that large numbers had to be employed to sustain an offensive despite losses to mechanical failure or vehicles foundering in intractable no man's land terrain. These losses, coupled with those from enemy artillery fire, later amounted to as high as 70% of the starters during some operations. Deploying small numbers of tanks would therefore cause the Allies to lose the element of surprise, allowing Germans to develop countermeasures.Anti-tank weapons
Because the German Army was the only force in need of anti-tank weapons, they were first to develop a viable technology to combat the armored vehicle. These technologies took three ammunition approaches: use of grenades by infantrymen, including the Geballte Ladung of several stick grenades bound together by pioneers; early attempts at the small-caliber anti-tank rifles like the bolt-action 13 mm Mauser 1918 T-Gewehr; 3.7 cm TaK Rheinmetall in starrer Räder-lafette 1916 anti-tank gun on a light carriage which could destroy a tank using large-caliber armor-piercing ammunition issued in 1917 to special commands; and the existing 77 mm field guns of the infantry division's artillery regiment were also eventually issued with special armor-piercing ammunition.File:Bundesarchiv Bild 183-R27012, Bei Cambrai erbeuteter englischer Panzer.jpg|thumb|right|A disabled Mark IV tank near Cambrai, 1917 – World War I
Anti-tank tactics
With the appearance of Allied tanks, the German Army were quick to introduce new anti-tank defense detachments within the pioneer battalions of the infantry divisions. These were initially issued 13 mm caliber long barrel rifles firing solid shot. However, these suffered from fouling after 2–3 rounds and had a recoil that was unsustainable by the mechanism or the rifleman. Stick grenades were used to destroy the tracks by individual pioneers, however this required accompanying machine-gunners to first separate the supporting Allied infantry line from the tanks, which proved difficult. Another tactic was to lure the tank beyond the German trench-line, re-establishing it just as the Allied infantry approached. The tank would then be engaged by the divisional 7.7 cm guns brought forward, that would try to disable the tracks with ordinary HE shells. If the crews of the disabled tanks refused to surrender, they were engaged with flamethrowers, or a mortar would be fired on the stricken vehicle until a direct hit was achieved on the top surface, usually resulting in an internal fire. Finally, anti-tank obstacles were prepared on the likely approaches by deepening and widening existing ground cratering, the precursors of the anti-tank trench. Finally in early 1917 the 3.7 cm TaK from Rheinmetall was rushed to the frontline, and proved effective in destroying the tanks despite limited elevation and traverse.Development between the world wars
Lack of consensus on the design and use of the tank after the First World War also influenced the development of its anti-tank countermeasures. However, because Germany was restricted by the Treaty of Versailles in its military capability, and there were no other challenges to France and Britain, very little development took place in anti-tank warfare until the 1930s.The Interwar period was dominated by the strategic thinking with fortified borders at its core. These included obstacles consisting of natural features such as ditches, streams and urban areas, or constructed obstacles such as anti-tank ditches, minefields, dragon's teeth, or log barriers. The pinnacle of this strategic thinking was considered to be the Maginot Line which replaced infantry-filled trenches with artillery-filled bunkers, including casemates housing 37 or 47 mm anti-tank guns, and steel turrets armed with a pair of machine guns and a 25 mm anti-tank gun, although Germany was forbidden to produce tanks. The construction was partially based on the Allied experience with the Hindenburg Line which was breached with tank support during the battles of Cambrai and St. Quentin Canal, although German Command was more impressed by the surprise achieved by the Canadian troops at the Battle of the Canal du Nord. This came to influence their planning in 1940.
The Maginot line defenses – up to deep from the forward positions to the rear line – were intended to prevent a surprise attack and delay any attack while the French Army was mobilized. With the relative numerical inferiority between the France and Germany, it was a more effective use of manpower. Within the line, passive anti-tank obstacles were supported by anti-infantry and anti-tank bunkers. After Belgium declared neutrality in 1936, France began work on extending the line along the Belgian border.
Improved artillery was seen as the quickest solution to anti-tank defense, and one of the earliest post-war anti-tank gun designs was the 25 mm Hotchkiss model from France. It was intended to replace an Atelier de Puteaux 37 mm weapon designed in 1916 to destroy machine gun positions. Rheinmetall commenced design of a 37 mm anti-tank gun in 1924 and the first guns were produced in 1928 as 3.7 cm Pak L/45, later adopted in Wehrmacht service as 3.7 cm Pak 36. It made an appearance during the Spanish Civil War, as did the Bofors 37 mm developed in Sweden, and used by many early Second World War combatants. The British Army accepted for service the Ordnance QF 2 pounder, which was developed as a tank gun. The Soviet Red Army after the Russian Civil War also begun a search for an anti-tank gun with a French Hotchkiss 37 mm L.33 tank gun, but soon upgraded this to a higher velocity L.45 Model 1935 while also making a licensed copy of the German 3.7 cm PaK 36. However, the Red Army was almost immediately taught a lesson about anti-tank warfare when a tank battalion sent to aid the Spanish Republicans in the Spanish Civil War was almost entirely destroyed in an engagement.
At this time, the predominant ammunition used against tanks was the armor-piercing kinetic energy shell that defeated armor by direct pressure, spiking or punching through it. During the late 1930s shaped charge ammunition was experimented with that used chemical energy for armor penetration. The shaped charge concept is officially known as the "Munroe Effect" and was discovered by accident decades earlier by Professor Charles E. Munroe at the U.S. Torpedo Station, Providence, RI. Professor Munroe was detonating different manufactured blocks of explosives on a sheet of armor plating and observed the blocks having the manufacturing letters recessed cut an imprint of the manufacturing letters into the armor plate—the birth of the shaped-charged explosive which focuses the blast energy caused by an indentation on the surface area of an explosive. Although shaped charges are somewhat more difficult to manufacture, the advantage is that the projectile does not require as high velocity as typical kinetic energy shells, yet on impact it creates a high-velocity jet of metal flowing like a liquid due to the immense pressure which hydrodynamically penetrates the armor and kills occupants inside. The depth of the penetration, though proportional to the length of the jet and the square root of its density, is also dependent on the strength of the armor. With the development of this new ammunition begun more advanced research into steel manufacturing, and development of spaced armor that caused "jet waver" by detonating prematurely or at the wrong angle to the surface of the main armor.
The only significant attempt to experiment in the use of tanks in the late 1920s was that of the British Army's Experimental Mechanized Force that influenced future development of tanks, armored troops and entire armies of both its future enemies and allies in the next war.
In Spain, the anti-tank defense of the Nationalists was organized by the Wehrmacht officers, and the anti-tank guns were incorporated into a system of obstacles that were constructed with the intent to stop an attack by tanks by slowing it down, separating them from supporting infantry with machine-gun and mortar fire, and forcing tanks to conduct deliberate head-on assaults with engineer support, or seek a less-defended area to attack. Minefields laid with purpose-designed mines were used for the first time, destroying tank tracks, and forcing combat engineers to clear them on foot. Delay meant that Nationalist field artillery could engage the lightly armored Soviet tanks. This meant a change in Republican operational and eventually strategic planning, and a more protracted combat operations, with more casualties at a greater cost.
The only change to the German anti-tank tactics of the First World War was that now an effective anti-tank weapon was available to support the defending infantry. However, the Soviet tanks armed with 45 mm guns easily destroyed the German light tanks.
Ironically, in the early 1930s until the Spanish War, German officers were conducting secret testing of a new way of employing tanks, infantry and artillery offensively in the Soviet Union with the cooperation of the Red Army. In Germany, these developments eventually culminated in tactics that later came to be known as Blitzkrieg, while in the Soviet Union they formed the core of the deep battle operational doctrine. The successful test of the latter was during the Battles of Khalkhin Gol although the Red Army foundered on the Mannerheim Line in 1940, largely due to the purge in the Officer Corps, claiming many of the senior proponents of the new doctrine. Anti-tank artillery would be included in mobile tank-led Wehrmacht and Red Army units due to the possibility of encountering enemy tanks in a meeting engagement.
The new doctrines of using the tank, were divided into infantry and cavalry schools of thought. The former regarded the tank as a mobile artillery system to be used for infantry support. This suggested that the infantry needed to be armed with integral anti-tank weapons. The latter advocated use of tanks in the traditional cavalry way of high-tempo attacks intended to outflank the enemy infantry and sever its communication lines. This approach suggested that the tank was the best anti-tank system, and only limited anti-tank troops were required to accompany them. For this reason the late 30s tank configurations came in a great diversity, ranging from light tankettes and cavalry tanks to multi-turreted heavy tanks resembling bunkers, all of which had to be considered in training by the anti-tank artillery troops. The development of these doctrines was the most significant influence on the rapid development in anti-tank technology and tactics in the Second World War.