Horizontal escalation is the process by which conflicts are heightened through geographical expansion with reasoning including diplomatic, economic, informational, and military components. This also includes international intervention as well as the geographical widening of combat operations. Horizontal escalation is a direct contrast to vertical escalation which employs types of weapons not previously used in the conflict. That type of escalation also allows attacking new types of targets in order to have an upper hand to the other combatant.[1] During the Cold War, the risks associated with using escalation were much broader and more diverse, due to the intensity of the current world events. Counterinsurgency and counter-terrorist operations were very prone to using horizontal escalation as a means of defense. Those two types of warfare are more likely to lead to horizontal escalation, because the area of conflict widens in efforts to eliminate enemy holdings or to punish other parties that support their enemy. In an era of such high intensity, in order to gain an upper hand, horizontal escalation was implemented.
Due to an unclear division between different types of escalation, some attacks can be classified as horizontal, vertical, or both.