Jaydeep Chaudhary asked: In military terms, what is the difference between intrusion, incursion, transgression and infiltration?

Deepak Kumar replies

Intrusion: As per the open-source definition, it means the movement of a unit or force or a military asset inside another nation’s specified operational area or territorial seas or territorial airspace for surveillance or intelligence gathering in times of peace, no war-no peace, or war. A characteristic feature of intrusion is that it is temporary in time and space and has to be vacated (or evicted).  

Incursion: As per the open-source definition, when an army crosses a border into another country for battle, they are making an incursion into the enemy territory. An incursion is an aggressive act of invasion as well as attack.

Transgression: When a military body of troops goes into the other side of the border assuming that it is their own territory due to the difference in the perception of the border itself.

Infiltration: A technique of tactical movement by small forces over land, air, or water through an area or territory occupied by friendly forces or an enemy, or in the close vicinity of enemy positions.  The movement is made at extended or irregular intervals. The aim of infiltration could be of temporarily occupying a feature of tactical importance, or locating a force to attack an enemy position from an unexpected direction or isolating an enemy locality for an attack by a larger follow-up force. It is inherent while infiltrating in enemy territory or close to it that contact with the enemy is avoided.

Posted on March 10, 2021

Views expressed are of the expert and do not necessarily reflect the views of the Manohar Parrikar IDSA or the Government of India.