Trench warfare

Cordons (border fortifications) were already built in antiquity, but it was usually not possible to defend more than one section due to the limited size of armies and short range of weapons. The great fortifications of antiquity, such as Hadrian's Wall (England), the Limes (Germany) or the Great Wall of China, are rather exceptions to the rule and served primarily to make the crossing of the border more difficult and to control it, but not to prevent it completely.

Field fortifications were rarely used in open field battles, as their construction takes considerable time. Field battles were comparatively short; the losing party often retreated to a fortress, which was then besieged. Nevertheless, even the Arab Muslims used Medina's trenches (Trench Battle of 627) to defend against cavalry.

Although both fortification and armament underwent massive development in the second half of the second millennium, even the introduction of firearms did not initially fundamentally change the fact that fortifications required large numbers of troops to defend them. Smaller units could not generate the necessary firepower to stop an attack.

The introduction of artillery already in the times of the Ottoman Empire and the battles that took place as in the siege of Vienna had a massive influence on the construction of the fortress and the siege. The attacking infantry was forced to approach the fortress in Approchen (approach trenches).

Important for the emergence of positional warfare and thus trench warfare was the introduction of large conscript armies at the time of the French Revolution and the Napoleonic Wars. Large armies made it more difficult to outmaneuver the enemy and attack the flanks. In particular, the introduction of machine guns such as the Gatling repeating gun made it increasingly necessary for infantry in field positions to protect themselves from attack and fire, including from increasingly effective artillery.

For trench warfare, in addition to field emplacement, the use of ground obstacles such as S-wire, Spanish Riders and Crow's Feet, and today, Bandstacheldraht, became increasingly important.

Crimean War

Before the siege of Sevastopol, the Russians had provisional trench systems built to defend the city. Rifles with rifled barrels (e.g. Enfield Rifled Musket) were used for the first time, which could be used to hit at a long distance. Although known for some time, the effectiveness of hand grenades was recognized in trench warfare.

War of Secession

The War of Secession was fought at the beginning with tactics from the Napoleonic era, but towards the end the war became a preview of the First World War. Thus, field fortifications became very important. These included the Spanish cavalry made of pointed wooden stakes, but also the first land mines. The Battle of Cold Harbor is considered the first open field battle, i.e. not a siege, which solidified into a trench warfare.

The Atlanta Campaign and the Siege of Petersburg near the end of the Civil War, with their trenches, were in marked contrast to early battles such as the First Battle of Bull Run.

Russo-Japanese War

The Russo-Japanese War (1904-1905) saw the first use of barbed wire and machine guns in the siege of Port Arthur. Infantry were also consistently equipped with breechloaders, which allowed a small force to unleash greater firepower. A small group of defenders could thus repel attackers much more easily with proper cover.

First World War

Main article: Trench warfare in World War I

With the outbreak of war, troops realized that the smallest amount of cover enabled the defender to repel an enemy attacking head-on. Frontal attacks resulted in dramatic casualties; therefore, flank attacks were seen as the only way to win. This led to a series of encircling maneuvers after the Battle of Marne, which ended only when both armies reached the coast. The trench system of the Western Front stretched from the North Sea to Switzerland.

After the First World War, trench warfare occurred only very rarely.

Second World War

The Second World War was characterized by the war of movement of mechanized troops and the air war on both the operational and tactical level, in the beginning mostly against an opponent who relied on fortifications and field positions such as the Maginot Line in France or the Metaxas Line in Greece. These were usually quickly broken through.

Nevertheless, even the Wehrmacht in the Russian campaign secured and defended larger sections of the front by infantry in extended field positions and bunker lines over longer periods of time and tried to compensate for a lack of mobile combat power with the Atlantic Wall. Each of these defensive systems could usually be breached by the attacker within a few hours and render the other adjoining sections obsolete.

This was also evident in the Indochina War as in the Battle of Điện Biên Phủ and the Korean War.

Iran-Iraq War

The most famous example of trench warfare after World War I was the Iran-Iraq War. In this war, both sides had a large infantry army, but very little armored vehicles, aircraft, or the necessary training. The result was a battle comparable to World War I, with trenches and the use of chemical weapons.

Eritrea-Ethiopia War

Another example is the war between Ethiopia and Eritrea, which also primarily involved infantry units.