This is coolbert:
That hierarchy of combat as enunciated by Dupuy. And as recognized by military professionals. Definitions as used to differentiate between the "levels and interactions of combat". All quotations direct from Dupuy.
From top to bottom, macro to micro:
1. War. Politics by other means! Two groups of persons using weapons in conflict, each attempting to impose their will on the other. "War is an armed conflict, or a state of belligerence, involving military combat between two factions, states, nations, or coalitions."
2. Campaign. A series of battles [perhaps even a single battle?] the goal of which is to achieve a strategic objective. "a phase of a war involving a series of operations . . . aimed toward achieving a single specific strategic objective or result".
3. Battle. Combat fought by units at the operational level. Normally fought by units at the corps level [multiple numbers of divisions] or greater.
4. Engagements. Combat fought normally by units no greater than divisional strength but no lesser than company size.
5. Actions. Combat fought normally by units no greater than battalion strength but no lesser than squad level. Lesser would be a fire team [half a squad] or a buddy team [two men].
6. Duel. Combat fought by two soldiers [sniper versus sniper perhaps] or two machines in opposition to one another [tank, plane, submarine].
There existing that overlap between engagement and action. An action normally lasting no more than a day, an engagement no more than a week.
Military professionals pay a lot or indeed any attention to these types of definitions and hierarchies? Devoted readers to the blog know better?