Trench warfare
Trench warfare has become archetypically associated with the First World War of 1914–1918, when the Race to the Sea rapidly expanded trench use on the Western Front starting in September 1914. By the end of October 1914 the whole front in Belgium and France had solidified into lines of trenches, which lasted until the last weeks of the war. Mass infantry assaults were futile in the face of artillery fire as well as rapid rifle and machine-gun fire. Both sides concentrated on breaking up enemy attacks and on protecting their own troops by digging deep into the ground. Trench warfare also took place on other fronts, including in Italy and at Gallipoli.
Anti-tank warfare
Anti-tank warfare arose as a result of the need to develop technology and tactics to destroy tanks during World War I. Since the first tanks were developed by the Triple Entente in 1916 but not operated in battle until 1917, the first anti-tank weapons were developed by the German Empire. The first developed anti-tank weapon was a scaled-up bolt-action rifle, the Mauser 1918 T-Gewehr that fired a 13mm cartridge with a solid bullet that could penetrate the thin armor of tanks of the time and destroy the engine or ricochet inside killing occupants. Because tanks represent an enemy's greatest force projection on land, anti-tank warfare has been incorporated into the doctrine of nearly every combat service since. Most predominant anti-tank weapons at the start of World War II were the tank-mounted gun, anti-tank guns and anti-tank grenades used by the infantry as well as ground-attack aircraft.