Attack, aggression, offense, offensive and their corresponding adjectives attacking, aggressive, offensive denote or describe action in a struggle for supremacy which must be met with defense or by means of defenses.
The terms are used not only of military operations but of competitive games or exhibitions of skill (as in boxing and fencing).
Attack implies the initiation of action; commonly, also, it suggests an attempt to catch the enemy or opposition off guard and therefore connotes suddenness, and often violence, of onset.
Aggression, which also implies initiation of hostile action, stresses rather a lack of provocation and a desire for conquest or domination.
Attack is applicable to any movement or action in a series of operations; aggression is applied chiefly to a war or to a type of fighting that involves invasion or encroachment on another’s territory and usually further connotes a determination to maintain the advantage of the attacking side.
Offense and offensive characterize the position or the methods of the attacking side. The noun is interchangeable with attack only when the latter word does not refer to a concrete action; thus, one may speak of methods of attack (or of offense) as contrasted with methods of defense but one would use “a war of offense'” (rather than of attack) and “readiness for an attack” (rather than for an offense).
Both words are distinguishable from aggression and aggressive, which in many ways they closely resemble, by their absence of suggestion of any motive or aim other than that of a desire for supremacy.
Offensive implies vigorously aggressive action especially in war; thus, when taking the offensive one carries on offensive operations. Offensive may also denote a particular campaign or episode marked by such action.