1
general::
Engaged in armed conflict; also, in a state of disagreement. This term may be used literally, usually of nations or smaller groups engaged in armed hostilities, as well as hyperbolically, describing a mild disagreement as "war," and figuratively, for an inner conflict. For example, The Greeks and Turks have been at war for many years (literally); The two families were at war about the bill for the wedding reception (hyperbolic); and, as Shakespeare put it in Measure for Measure (2:2): "I am at war ‘twixt will and will not" (inner conflict of indecision). [Late 1300s]
American Heritage Idioms