Main Page | See live article | Alphabetical index In military science, defense is the art of preventing an enemy from conquering territory; usually via fortifications. Defense may also be a euphemism for war. It was well-known ages ago that the defending side needs far less resources to keep fighting than the offensive side. See also: Arms trade This article is a stub. You can help Wikipedia by fixing it. This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License.