How did trench warfare and new weapons technology impact the course of world war 1?

Probably the most important was the introduction of high explosive shells, which dramatically increased the lethality of artillery over the 19th-century equivalents. Trench warfare led to the development of the concrete pill box, a small, hardened blockhouse that could be used to deliver machine gun fire.

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an era of negotiation.

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c. troops marched forward in close formation against newer, more accurate weapons