These words refer to a physical and hostile entering of someone else’s territory. Raid suggests an organized but short-range and temporary encroachment: boys planning a raid on the neighbour’s orchard; an unexpected raid on the jungle stronghold of the enemy. As in these examples, stealth and surprise may be suggested as planned elements of a raid . The word can be used humorously for less hostile acts: laying in a supply of meat and salad for the inevitable midnight raid on the refrigerator. Foray suggests a more scattered, less organized overrunning of territory than raid; it may be haphazard and impulsive as well and even more short-ranged and short-lived. A foray’s sole motivation may be an intent to wreak gratuitous havoc or to plunder and pillage: students who went on forays in the town; a foray behind enemy lines. A sorties is a special kind of raid. Originally meaning a dashing outbreak by a besieged garrison, it has come to refer almost exclusively to an operation by an aircraft in wartime: He flew three sorties in one day over France.

Incursion is the most formal of these words and is often used in a technical sense to indicate a violation of a nation’s territory by another nation: arguing that the flight could be considered an incursion on Soviet airspace. In this sense it may suggest any encroachment: an incursion on civic rights. The word can also be used technically for any hostile entrance, usually sudden, into another’s territory: an armed incursion into the Gaza strip. Invasion resembles raid in suggesting an organized and well-planned violation of territory, but it specifically suggests a much more complicated and long-range operation that is usually carried out with the intention of effecting a seizure or change of a permanent sort: the massive Allied invasion of Normandy. Occasionally the word suggests a large-scale but unplanned incursion : the Danish invasion of Britain that occurred over several centuries and took the form of sporadic but repeated raids of forays. The word can also suggest any unwanted intrusion : an invasion of privacy.