Western Front
When the Schlieffen Plan did not work for Germany they switched to Trench Warfare.
The Western Front!
The Western Front (in France and Belgium) where both sides were very evenly matched, and the defense proved much stronger than the offense. On other fronts in World War 1, trench warfare was not necessary.
your answer is in the category trench warfare was one of them there was also air warfare
Trench warfare developed on the Western Front during World War I due to the stalemate between the Allied and Central Powers, with both sides digging trenches for protection. On the Eastern Front, the vast open spaces and more fluid military tactics made trench warfare less practical.
Gas and artillery warfare. Artillery --> Guns.
The two major fronts of World War I most closely associated with trench warfare are the Western Front and the Eastern Front. The Western Front, characterized by a stalemate between Allied and Central Powers, saw extensive trench systems stretching from the North Sea to Switzerland. While trench warfare was less prevalent on the Eastern Front, it did occur in certain areas, particularly in the later stages of the war. The harsh conditions and high casualty rates on the Western Front epitomized the brutal nature of trench warfare.
Things associated with the Western Front include: Trench warfare Battles between Germany and France Poisonous gas
Mostly on the western front, but also on some other fronts like Gallipoli and the eastern front.
The technological innovations led to the trench stalemate on the western front in various ways. Each army developed entrenchments which they intended to use in the war and this is what propagated the Trench Warfare.
The Germans faced France and French colonial forces, Britain and Britich colonial forces, and, eventually, the Americans on their Western Front in trench warfare. Austrian and Germans faced the Russians for a time on the Eaastern Front, some of that in trench warefare.