Editing Military tactics (section)

===Protection and security===
[[Body armor|Personal armour]] has been worn since the classical period to provide a measure of individual protection, which was also extended to include [[barding]] of the mount. The limitations of armour have always been weight and bulk, and its consequent effects on mobility as well as human and animal endurance. By the 18th and 19th centuries, personal armour had been largely discarded, until the re-introduction of [[Combat helmet|helmet]]s during World War I in response to the firepower of artillery. [[Armoured fighting vehicle]]s proliferated during World War II, and after that war, body armour returned for the infantry, particularly in Western armies. [[Fortification]]s, which have been used since ancient times, provide collective protection, and modern examples include [[entrenchment (fortification)|entrenchments]], [[roadblock]]s, [[barbed wire]] and [[minefield]]s. Like obstacles, fortifications are often created by military engineers.{{sfn|Holmes et al.|2001|p=895}}