Kasserine Pass, gap, 2 mi (3.2 km) wide, central Tunisia, in the Grand Dorsal chain (an extension of the Atlas Mts.). A key point in the Allied offensive in Tunisia in World War II, the pass was the scene of an Axis breakthrough (Feb. 20, 1943), but it was retaken with very heavy losses by U.S. forces on Feb. 25. See North Africa, campaigns in.