Forward Operating Base (FOB) Kalsu (also referred to as Camp Kalsu and Contingency Operating Site (COS) Kalsu) was a U.S. military installation located in Iskandariya, a city in the Babil province of Iraq, about 20 miles south of Baghdad. Named after Bob Kalsu, a Buffalo Bills offensive lineman and lieutenant who was the only active NFL player to die in Vietnam, FOB Kalsu was one of the many bases established by the U.S. military during the Iraq War.

FOB Kalsu was strategically positioned in the “Triangle of Death,” an area so named due to the high level of insurgent activity. This location made it a crucial hub for operations in this region, allowing U.S. and coalition forces to effectively conduct and respond to developments in the area.

Several different units were stationed at FOB Kalsu throughout its operation. Notably, elements of the 2nd Brigade, 10th Mountain Division, the 2nd Brigade, 3rd Infantry Division, and the 172nd Infantry Brigade were among those that called FOB Kalsu home at various points in time. These units carried out diverse operations, including counterinsurgency missions, patrols, and training of Iraqi forces, contributing to the broader mission of stabilizing the region.

Facilities at FOB Kalsu included not only housing and dining for troops, but also operation centers, training areas, and logistical support. The base was designed to support the personnel stationed there, providing the necessary facilities to maintain their operational readiness and morale during their deployment.