Even the Iraq-Iran war devolved into a sort of trench warfare with a static front and battles of attrition. In the Soviet union's struggle against Germany they employed trenches too, such as at the Isthmus of Perekop (litteraly Isthmus of the Trench). There they had large minefields, barbed wire and defensive networks. Another example are the battles for El Alamein.
Classic trench warfare at the Karelian Isthmus.
