A military attack is an offensive action taken by a military force against an enemy. A RAID is a surprise attack on an enemy, usually involving a small number of troops. A SIEGE is a prolonged military operation in which enemy forces surround a town or building and block the supply of food, water, and other necessities. An ASSAULT is a violent attack on an enemy, often involving a large number of troops. A SORTIE is a short mission undertaken by a military force, typically involving a small number of troops. A THRUST is a forceful attack on an enemy, usually involving a large number of troops.