What term is used to describe entering another country by force?

The term used to describe entering another country by force is "invasion." An invasion typically involves a large-scale military action where armed forces move into another nation with the intention of occupying territory or forcing capitulation. This action can lead to significant changes in control or governance in the invaded region and often results in conflict, warfare, or military engagements.

In contrast, the other terms refer to different contexts or aspects of military or territorial actions. "Storming" usually refers to a rapid, forceful assault on a fortified position or building rather than a country as a whole. "Encroachment" is typically used in a legal or territorial sense to imply gradual intrusion into someone else’s space or rights, rather than a full-scale military operation. "Occupation" refers to controlling a territory, often after an invasion has successfully occurred, but it does not specifically describe the act of forcibly entering that territory.