A sapper or combat engineer is an combatant soldier who performs a wide variety of combat engineering duties; typically including, but not limited to, bridge-building, laying or clearing minefields, demolitions, field defenses, general construction and building, as well as road and airfield construction and repair. He is also trained to serve as an infantryman when needed in both defensive and offensive operations and is fully involved in modern counter-insurgency operations. A sapper's tasks have, throughout history, including modern day counter-insurgency operations, been devoted to the mission-critical tasks involving facilitating movement and logistics of allied forces and impeding that of enemies.