Why was World War One fought in trenches on the western front?

Starael is kind of right but very simplistic. The real need for trenches on the Western Front of the First World War was because military technology had advanced beyond military tactics. Machine guns and machine gun emplacements rendered the cavalry (horse) and infanrty assaults obsoelete.

Once the initial Central Powers (Imperial Germany and Austria) offensive slowed down and the French and British were able to mount counter offensives both sides began digging in...digging trenches. Trenches had actually been used to good effect prior to WW1 in the Crimean War (charge of the light brigade) and the American Civil War (the Petersburg and Richmond defenses). There is a link to a good wikipedia article on Trench Warfare...you also might like to follow this up with a nice retelling of the opening of the entire conflict in Barbara Tuchman's "Guns of August."

A brilliant book that is still readily available. Good luck. More.

I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.