http://www.dtic.mil/doctrine/dod_dictionary/index.html

Type in "War" and see what comes up.

(For those who can't wait: 111 results, but no actual definition for "war" itself. With the advent of Irregular warfare, which covers many area that are clearly not "war" I suspect it just to the point where to write a definition for war that included everything that the DOD wants to include under that umbrella it simply became to embarrassingly ridiculous to publish. Easier to just delete it and let everyone merrily go on making virtually anything and everything "war."

After all, if we actually live in an era of 'forever war" or "perpetual conflict" as some dark souls proclaim, I guess war is everything, and everything is war. Cool. (not!)

Someone needs to turn this donkey cart of doctrine around before the good idea fairly drives it off a cliff.

If you are really feeling adventurous type in "insurgency"

insurgency
(DOD) The organized use of subversion and violence by a group or movement that seeks to overthrow or force change of a governing authority. Insurgency can also refer to the group itself.
Source: JP 3-24

Seems semi-reasonable, but has been heavily shaped to fit recent US operations. Consider the Army's definition from 1962 in comparison:

"Insurgency is a condition of subversive political activity, civil rebellion, revolt, or insurrection against a duly constituted government or occupying power wherein irregular forces are formed and engage in actions, which may include guerrilla warfare, that are designed to weaken and overthrow that government or occupying power."

While I have a couple minor quibbles with the 1962 version, it is a very workable understanding of insurgency. The current version? That is simply our perspective of Iraq and Afghanistan, and forces our thinking into a narrow little box.