French lookouts posted in a barbed-wire-covered trench. The use of barbed wire in warfare was recent, having only been used for the first time in limited form during the Spanish-American War. All sides in World War I used extensive networks of barbed wire entanglements to prevent ground troops from moving forward. The effectiveness of the wire drove the development of technologies like the tank, and wire-cutting explosive shells set to detonate the instant they made contact with a wire.