The M113s were instrumental in conducting Reconnaissance in force (RIFs), search and destroy missions, and large invasions (incursions) such as the U.S. invasion of Cambodia on 1 May 1970 and later Laos (Operation Lam Son 719) in 1971; all of which used the M113 as the primary work horse for moving the ground armies. While operating with cavalry and armor units, the M113s often worked in conjunction with U.S. M48 Patton and M551 Sheridan tanks. During the Vietnam War, U.S. Army gun trucks, along with V-100 armored cars, conducted convoy escorts for military traffic.