Editing Trench warfare (section)

== Later use ==

[[File:Manoeuvre tourelle.gif|thumb|left|Side view diagram of a gun in a retractable turret, in block 3 in [[Ouvrage Schoenenbourg]] of the [[Maginot Line]]]]
[[File:Força Expedicionária Brasileira - Força Expedicionária Brasileira na Itália (14).jpg|thumb|left|Soldiers of the [[Brazilian Expeditionary Force]] in a trench during the [[Battle of Montese]], 1945]]

=== Spanish Civil War ===
Trenches were often used in both sides<ref>[https://www.historyextra.com/period/spains-very-international-civil-war/ Spain's very international civil war]</ref><ref>[https://libcom.org/library/quiet-fronts-michael-seidman Quiet fronts in the Spanish civil war]</ref> particularly the [[Nationalist faction (Spanish Civil War)|Nationalists]] whose military ground doctrine emphasized static defence. The [[Republican faction (Spanish Civil War)|Republicans]] also employed the use of trenches, but also [[human wave attack]]s most notably during their defence of [[Casa de Campo]] in the [[Siege of Madrid]].

=== World War II ===
In the decade [[Causes of World War II|leading up to World War II]], the French built the [[Maginot Line]], based on their experience with trench warfare in World War I. The Maginot Line was an extensive [[State of the art|state-of-the-art]] defensive system far superior to any previous trench system: a chain of massive constructions of concrete, iron, and steel fortresses, bunkers, retractable turrets, outposts, obstacles, and sunken artillery emplacements, linked by [[tunnel network]]s.  It covered the length of the Franco-German border and was {{convert|20-25|km}} wide. It was supported by numerous underground barracks, shelters, ammunition dumps and depots, with its own telephone network and [[narrow gauge]] railways with [[Armoured train|armoured locomotives]], backed up with heavy [[Railway gun|rail artillery]]. French military experts placed high value on the line, saying it would curb German aggression, as any invasion force would be halted long enough for French forces to mobilize and counterattack. Furthermore, [[French war planning 1920–1940|French military planning during the inter-war period]] believed that the line would force the [[Nazi Germany|Germans]] to invade Belgium. This would allow any future conflict to take place off of French soil. By bypassing the Maginot Line and fighting the Belgian Army, it would allow the French military to move its best formations to counter. In the [[Battle of France]], Germany invaded Belgium and the best Anglo-French forces moved to meet them as planned. However, the Germans had only recently changed their plans from what the French had anticipated would happen. Instead of an attack through central Belgium, the main German attack was delivered through the [[Ardennes forest]]. Inter-war French planning believed it would take the Germans 9 days to move forces through this area, and that it could be held by small forces. The German forces outpaced expectations and soon crossed into France between the main French forces and the Maginot Line. They then advanced towards the English Channel, and surrounded the Anglo-French armies. Small secondary German attacks concentrated at a few points in the Line had mixed success. The bulk of the Maginot Line was untouched, its garrisons withdrawn, and flanked. Due to the lack of combat, much of it has survived.

The return of [[Maneuver warfare|mobile warfare]] in World War II reduced the emphasis of trench warfare, as defenders commonly lacked the time to build up such battlefield defences before they were forced to redeploy, due to the more rapidly-changing strategic situation. But trench systems were still effective, wherever mobility was limited, the front lines were static, or around known critical objectives that could not be bypassed. More quickly improvised [[defensive fighting position]]s, using "scrapes" or "foxholes", that can be supplemented by [[sand bag]]s, local materials, debris, or rubble, remain in common use. These are typically improved and expanded by the defenders, eventually becoming full trench systems, if given enough time and resources.

In the [[Winter War]], the [[Mannerheim Line]] was a system of flexible field fortification for the defending Finns. While having very few bunkers and artillery compared to heavy defence lines like the [[Maginot Line]], it allowed defensive platoons to regroup between field fortifications ([[Field fortifications|wood-earth firing posts, dugouts and pillboxes]]) instead of locking them into bunkers, while forcing the invaders to attack trenches as in World War I without armor and direct fire support. It caused heavy losses to the Soviets and repelled them for two months.<ref>{{Cite book|title=The Árpád-line|last=Szabó|first=János J.|publisher=Timp|year=2002|isbn=963-204-140-2|location=Budapest|pages=6–67}}</ref>

[[File:The British Army in North Africa 1940 E932.jpg|thumb|A British trench mortar post in North Africa, 1940]]
[[File:62. armata a Stalingrado.jpg|thumb|upright=1.0|[[Soviet Union|Soviet]] soldiers running through the ruins of [[Battle of Stalingrad|Stalingrad]], 1942]]

At the [[Battle of Sevastopol]], [[Red Army]] forces successfully held trench systems on the narrow peninsula for several months against intense German bombardment. The Western Allies in 1944 broke through the incomplete [[Atlantic Wall]] with relative ease through a combination of amphibious landings, naval gunfire, air attack, and [[airborne troops|airborne]] landings. Combined arms tactics where infantry, artillery, armour and aircraft cooperate closely greatly reduced the importance of trench warfare. It was, however, still a valuable method for reinforcing natural boundaries and creating a line of defence. For example, at the [[Battle of Stalingrad]], soldiers on both sides dug trenches within the ruins; as well in the [[Battle of Hurtgen Forest]], both American and German soldiers also dug trenches and [[Fox hole|foxholes]] in the rugged woods of the forest which led to continuous stalemates and failed offensives that lasted for months, which was reminiscent of the trench warfare of World War I. The [[Battle of the Scheldt]], due to the geography of the battle field greatly involved the use of trench warfare. In addition, before the start of the [[Battle of Kursk]], the Soviets constructed a system of defence more elaborate than any they built during World War I.<ref>{{Cite web |date=2009-10-29 |title=Battle of Kursk |url=https://www.history.com/.amp/topics/world-war-ii/battle-of-kursk |access-date=2022-12-27 |website=www.history.com}}</ref> These defences succeeded in stopping the German armoured pincers from meeting and enveloping the salient.<ref>{{cite web |last1=Remson |first1=Andrew |last2=Anderson |first2=Debbie |url=http://geocities.com/armysappersforward/kursk.htm |title=Mine and Countermine Operations in the Battle of Kursk: Final Report |date=25 April 2000|access-date=2025-05-13 |url-status=dead |archive-url=https://web.archive.org/web/20091026215617/http://geocities.com/armysappersforward/kursk.htm |archive-date=October 26, 2009 }}</ref>

The [[Italian Campaign (World War II)|Italian Campaign]] fought from 1943 until the end of the war in Europe largely consisted of the Allies storming strongly fortified German lines which stretched from one coast, over the mountains to the other coast. When the Allies broke through one line, the Germans would retreat up the peninsula to yet another freshly prepared fortified line.
 
At the start of the [[Battle of Berlin]], the last major assault on Germany, the Soviets [[Battle of the Seelow Heights|attacked over the river]] [[Oder]] against German troops dug in on the [[Seelow Heights]], about {{convert|50|km|mi|abbr=on}} east of Berlin. Entrenchment allowed the Germans, who were massively outnumbered, to survive a bombardment from the largest concentration of artillery in history; as the Red Army attempted to cross the marshy riverside terrain they lost tens of thousands of casualties to the entrenched Germans before breaking through.

During the [[Pacific War]], the [[Empire of Japan|Japanese]] used a labyrinth of underground fixed positions to slow down the Allied advances on many Pacific Islands. The Japanese built fixed fortifications on [[Iwo Jima]], [[Okinawa Prefecture|Okinawa]], and [[Peleliu]] using a [[tunnel network|system of tunnels]] to interconnect their fortified positions. Many of these were former mine shafts that were turned into defence positions. Engineers added sliding armored steel doors with multiple openings to serve both artillery and machine guns. Cave entrances were built slanted as a defence against grenade and flamethrower attacks. The caves and bunkers were connected to a vast system throughout the defences, which allowed the Japanese to evacuate or reoccupy positions as needed, and to take advantage of shrinking interior lines. This network of [[bunker]]s, tunnels, and [[Pillbox (military)|pillboxes]] favoured the defence. For instance, the Japanese on [[Battle of Iwo Jima|Iwo Jima]] had several levels of honeycombed fortifications. The Nanpo Bunker (Southern Area Islands Naval Air HQ), which was located east of Airfield Number 2, had enough food, water and ammo for the Japanese to hold out for three months. The bunker was 90 feet deep and had tunnels running in various directions. Approximately 500 55-gallon drums filled with water, kerosene, and fuel oil for generators were located inside the complex. Gasoline powered generators allowed for radios and lighting to be operated underground.<ref>{{Cite book|title=A Tomb Called Iwo Jima|last=King|first=Dan|publisher=Pacific Press|year=2014|isbn=978-1500343385|pages=58–59}}</ref> The Japanese caused the American advance to slow down and caused massive casualties with these underground fixed positions. The Americans eventually used [[flamethrower]]s and systematic hand-to-hand fighting to oust the defenders.<ref name=WW2MMDb_Letters>{{cite web |url=http://www.worldwar2database.com/html/letters_from_iwo_jima.htm |title=Letters from Iwo Jima |publisher=World War II Multimedia Database |url-status=dead |archive-url=https://web.archive.org/web/20071212233438/http://worldwar2database.com/html/letters_from_iwo_jima.htm |archive-date=12 December 2007 |df=dmy }}</ref><ref name=BattleFleet_IwoDefense>{{cite web|url=http://www.battle-fleet.com/pw/his/Battle-Iwo-Jima-Defense.htm|title=Battle of Iwo Jima—Japanese Defense|work=World War II Naval Strategy|access-date=11 November 2018|archive-date=5 August 2017|archive-url=https://web.archive.org/web/20170805015433/http://www.battle-fleet.com/pw/his/Battle-Iwo-Jima-Defense.htm|url-status=dead}}</ref> The American ground forces were supported by extensive [[naval artillery]], and had complete [[air supremacy]] provided by [[U.S. Navy]] and [[United States Marine Corps|Marine Corps]] aviators throughout the entire battle.<ref>{{cite video | date = 19 March 1945 | title = Video: Carriers Hit Tokyo! 1945/03/19 (1945) | url =https://archive.org/details/1945-03-19_Carriers_Hit_Tokyo | publisher =[[Universal Newsreel]] | access-date = 22 February 2012 }}</ref>

=== Post-1945 to modern day ===
[[File:101st Airborne Division - Vietnam 01.jpg|thumb|Men of the 1st Brigade, [[101st Airborne Division]], fire from old [[Viet Cong]] trenches during the [[Vietnam War]].]]
Trench warfare has been infrequent in recent wars. When two large armoured armies meet, the result has generally been mobile warfare of the type which developed in World War II. However, trench warfare re-emerged in the latter stages of the [[Chinese Civil War]] ([[Huaihai Campaign]]) and the [[Korean War]] (from July 1951 to its end).

During the Cold War, [[NATO]] forces routinely trained to fight through extensive works called "Soviet-style trench systems", named after the [[Warsaw Pact]]'s complex systems of field fortifications, an extension of Soviet field entrenching practices for which they were famous in their [[Great Patriotic War]] (the Eastern Front of World War II).

In the [[Iran–Iraq War]], both armies lacked training in [[combined arms]] operations. Both countries often prepared entrenched defensive positions and [[Tunnel network|tunnels]] to protect and supply the cities and bases throughout the regions. Military mobility was drastically reduced; hidden [[anti-tank mine]]s, and unstable footing made it easy to slide into or get buried in a camouflaged [[anti-tank trench]]. Tactics used included trench warfare, machine gun posts, bayonet charges, booby traps, use of barbed wire across trenches and on [[no-man's land]], Iranian [[human wave attack]]s, and Iraq's extensive use of chemical weapons such as [[mustard gas]] against Iranian troops.<ref name="Benschopvan der Schans1997">{{cite journal|last1=Benschop|first1=H. P.|last2=van der Schans|first2=G. P. |last3=Noort |first3=D. |last4=Fidder|first4=A.|last5=Mars-Groenendijk|first5=R. H.|last6=de Jong|first6=L. P. A.|title=Verification of Exposure to Sulfur Mustard in Two Casualties of the Iran-Iraq Conflict|journal=Journal of Analytical Toxicology|volume=21|issue=4|year=1997|pages=249–251|issn=0146-4760|doi=10.1093/jat/21.4.249|pmid=9248939|doi-access=free}}</ref>

Iraq again attempted to use trenches during the 1991 [[Gulf War]]. After the [[Invasion of Kuwait]], [[Saddam Hussein]] with the objective of forcing the [[Coalition of the Gulf War|coalition]] to engage in costly World War I-era trench warfare, ordered the construction of a massive fortification line in the [[Kuwait–Saudi Arabia border|Saudi-Kuwait border]], consisting of regular trench lines, "flame trenches" (ditches filled with oil to be ignited in case of attack), sand [[Berm|berms]], trench works, anti-tank ditches, barbed wire and [[Minefield|minefields]], which became known as the [[Saddam Line]].<ref>{{cite web |author=Staff |date=n.d. |title=Iraq and the Gulf War 1990-1991 |url=http://www.fas.org/irp/gulf/cia/960702/70086_01.htm |access-date=February 24, 2012 |publisher=([[CIA Directorate of Intelligence|Directorate of Intelligence]] document) [[United States Department of Defense|U.S. Department of Defense]] (via the [[Federation of American Scientists]])}}</ref><ref name="LATimes">{{cite news |author=Drogin, Bob |author-link=Bob Drogin |date=February 25, 1991 |title='Saddam Line' Falls Easily to Marines |work=[[Los Angeles Times]] |url=https://www.latimes.com/archives/la-xpm-1991-02-25-mn-1412-story.html |access-date=February 24, 2012}}</ref><ref name=":03">{{Cite web |title=The 'Bulldozer Assault' of Desert Storm Saw the US Army Opt Out of Trench Warfare |url=https://www.military.com/history/bulldozer-assault-of-desert-storm-saw-us-army-opt-out-of-trench-warfare.html |access-date=2022-08-27 |website=www.military.com|date=18 April 2022 }}</ref> However, at the start of the [[Liberation of Kuwait campaign|Liberation of Kuwait]], the US forces charged the Iraqi lines with [[M1 Abrams]] tanks modified with [[Demining|minesweeping ploughs]] and [[M728 Combat Engineer Vehicle]]s which buried the trench lines, and in many cases, buried Iraqi troops alive.<ref name=":03" /> In less than three hours after the initial assault, US and coalition forces had already broken through and bypassed the Saddam line and the rest of war was composed by highly mobile [[manoeuvre warfare]] focusing on overwhelming power against the Iraqis.<ref>{{cite book |author=Kellner, Douglas |title=The Persian Gulf TV War |publisher=[[Westview Press]] (via the [[University of California, Los Angeles]]) |year=1992 |isbn=978-0-8133-1614-7 |location=Boulder, Colorado |chapter=Chapter 8 – Countdown to the Ground War |author-link=Douglas Kellner |access-date=February 24, 2012 |chapter-url=http://gseis.ucla.edu/faculty/kellner/essays/gulfwarch8.pdf}}</ref><ref name=":03" />

[[File:U.S. Soldiers and Afghan soldiers provide security while standing behind HESCO barriers during strongpoint construction at Zharay district, Kandahar province, Afghanistan, Feb 120210-A-QD683-134.jpg|thumb|[[History of the Afghan Armed Forces (2002–2021)|Afghan]] and U.S. soldiers provide security while standing behind a [[blast wall]] made from [[Hesco bastion|HESCO bastions]]  Afghanistan, 2012]]
There was an extensive trench system inside and outside the city during the 1992–1996 [[Siege of Sarajevo]]. It was used mainly for transportation to the front-line or to avoid [[sniper]]s inside the city. Any pre-existing structures were used as trenches; the best known example is the bobsleigh course at [[Trebević]], which was used by both [[Serbs|Serb]] and [[Bosniaks]] forces during the siege.<!--The source needs to state that this siege involved  trench warfare and not just traditional siege works used in [[Investment (military)]] ie circumvallation and contravallation-->

In the [[Eritrean-Ethiopian War]] of 1998–2000, the widespread use of trenches raised comparisons to the trench warfare of World War I.<ref>{{cite book |first=Gebru |last=Tareke |title=The Ethiopian Revolution: War in the Horn of Africa |location=New Haven |publisher=Yale University |year=2009 |page=345 |isbn=978-0-300-14163-4}}</ref> According to some reports, trench warfare led to the loss of "thousands of young lives in human-wave assaults on Eritrea's positions".<ref>{{cite news |last=Fisher |first=Ian |url=https://www.nytimes.com/1999/08/23/world/peace-deal-may-be-near-for-ethiopia-and-eritrea.html |title=Peace Deal May Be Near for Ethiopia and Eritrea|date=23 August 1999|newspaper=[[The New York Times]]}}</ref> The Eritrean defences were eventually overtaken by a surprise Ethiopian pincer movement on the Western front, attacking a mined, but lightly defended mountain (without trenches), resulting in the capture of Barentu and an Eritrean retreat. The element of surprise in the attack involved the use of donkeys as pack animals as well as being a solely infantry affair, with tanks coming in afterwards only to secure the area.<ref>{{cite news|author=Bond, Catherine|agency=Associated Press and Reuters |url=http://archives.cnn.com/2000/WORLD/africa/05/22/ethiopia.eritrea/ |title=Eritrean independence celebrations muted as Ethiopian troops advance |website=Archives.cnn.com|date=22 May 2000 |archive-url=https://web.archive.org/web/20080618113000/http://archives.cnn.com/2000/WORLD/africa/05/22/ethiopia.eritrea/ |archive-date=18 June 2008}}</ref>

The [[Korean Demilitarized Zone|front line in Korea]] and the [[Line of Control]] in [[Kashmir]] between Pakistan and India are two examples of demarcation lines which could become hot at any time. They consist of kilometres of trenches linking fortified strongpoints and in Korea surrounded by millions of [[land mine]]s. The [[Indian Army]] has fortified the LOC with 900 [[Gun turret fortifications|fixed tank turrets]].<ref>{{cite web | url=https://www.indiatoday.in/india/story/transformers-retired-tanks-functioning-as-bunkers-975973-2017-05-08 | title=Transformers: Retired tanks functioning as bunkers | date=9 May 2017 }}</ref> The borders between [[Armenia]] and [[Azerbaijan]] amid the ongoing [[Nagorno-Karabakh conflict]] are also heavily fortified with trenches and barbed wire, with the two sides regularly trading fire.<ref>{{cite news |last1=Rettman |first1=Andrew |title=Armenia-Azerbaijan war: line of contact |url=https://euobserver.com/foreign/137017 |access-date=24 July 2018 |work=EUobserver |date=24 February 2017 |language=en}}</ref>

==== Russo-Ukrainian War ====
[[File:Battle of Bakhmut 3.jpg|thumb|right|200px|Ukrainian soldier in a trench during the [[Battle of Bakhmut]]]]
In the [[Russo-Ukrainian War]], to safeguard and assert their territories, both Ukrainian and [[Pro-Russian conflict in Ukraine|Russian proxy forces]] have resorted to digging small trench networks and engaging in warfare akin to the trench fights of World War I in some aspects. This involves soldiers spending extended periods within trenches, employing cement mixers and excavators to construct tunnel networks and deep bunkers for added protection.<ref>{{cite magazine |last1=Laurent |first1=Olivier |title=Go Inside the Frozen Trenches of Eastern Ukraine |url=https://time.com/3715642/ukraine-russia-trenches-photos/ |access-date=24 July 2018 |magazine=Time |language=en-us}}</ref> After the [[Minsk Protocol|Minsk peace agreements]] the front lines did not move significantly until the [[2022 Russian invasion of Ukraine]], as both sides dug elaborate networks of trenches and deep bunkers for protection and the two sides mostly fired mortars and sniper shots at each other.<ref>{{cite news |last1=Brown |first1=Daniel |title=Here's what it's like inside the bunkers Ukrainian troops are living in every day |url=https://www.businessinsider.com/heres-what-the-bunkers-ukrainian-troops-dig-for-protection-look-like-2017-8?r=US&IR=T#/#the-soldiers-first-dig-out-a-hole-which-is-usually-at-least-waist-deep-then-they-put-down-a-layer-of-timber-and-cover-it-with-dirt-the-bunkers-are-also-sometimes-fortified-with-concrete-1 |access-date=24 July 2018 |work=Business Insider Australia |date=16 August 2017 |language=en}}</ref>

The 2022 invasion also saw the construction of trench lines and similar defensive structures by both sides, especially after the end of the initial Russian offensive, resulting in a static war of attrition with slow advances and artillery duels, especially in [[Donetsk Oblast]].<ref>{{Cite web |date=2022-06-14 |title=Echoes of WWI in Ukraine war's artillery duels and trenches |url=https://www.france24.com/en/live-news/20220614-echoes-of-wwi-in-ukraine-war-s-artillery-duels-and-trenches |access-date=2022-11-26 |website=France 24 |language=en}}</ref> Pictures of muddy trenches, stumps of charred trees in a shell-pocked landscape made the [[Battle of Bakhmut]] emblematic for its trench warfare conditions, with neither side making any significant breakthroughs amid hundreds of casualties reported daily.<ref>{{Cite web |date=2022-11-28 |title=Fighting in east Ukraine descends into trench warfare as Russia seeks breakthrough |url=https://www.theguardian.com/world/2022/nov/28/hundreds-dead-in-ukraine-as-frontline-trench-war-escalates |access-date=2022-11-29 |website=The Guardian |language=en}}</ref><ref>{{Cite web |last=Ellyatt |first=Holly |title=Trenches, mud and death: One Ukrainian battlefield looks like something out of World War I |url=https://www.cnbc.com/2022/11/30/trenches-endless-mud-and-death-the-battle-of-bakhmut.html |access-date=2022-12-15 |website=CNBC |date=30 November 2022 |language=en}}</ref> Modern technology has adapted to the trench warfare, and use of drones and mobile networks is common. The battlefield has been described as "World War I with 21st-century Intelligence, Surveillance, and Reconnaissance".<ref>{{Cite web |url=https://www.businessinsider.com/ukraine-using-world-war-i-era-machine-guns-sniper-traps-to-fight-off-russia-2023-3|title=Ukraine's troops fight off 'massive' Russian attacks in Bakhmut with World War I-era machine guns and sniper traps.|website=businessinsider |date=30 November 2022 |language=en}}</ref>