| Project Copper | |
|---|---|
| Part of Vietnam War (Laos • Cambodia • Vietnam) | |
| Type | Coordinated military action |
| Location | |
| Planned by | RLAF, FANK, CIA, DOD |
| Commanded by | Lim Sisaath, Hatsaty Sinsay, Lon Non |
| Objective | Interdict the Sihanouk Trail; train irregular forces |
| Date | Late-1970—May 1971 |
| Executed by | RLAF, FANK, CIA, DOD, ARVN |
| Outcome | Interdiction failed, project abandoned |
| Project Copper | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| |||||||||
| Belligerents | |||||||||
 Kingdom of Laos Khmer RepublicSupported by  United States South Vietnam |
 North Vietnam | ||||||||
| Commanders and leaders | |||||||||
|
Hatsaty Sinsay Lim Sisaath Lon Non | |||||||||
| Units involved | |||||||||
|
Three commando battalions 15 Brigade d'Infanterie Bataillon Chasseur 202 | |||||||||
| Casualties and losses | |||||||||
| 82 | Unknown | ||||||||
Project Copper was a coordinated military action undertaken by the Kingdom of Laos and the Khmer Republic from 1 January–May 1971. It used U.S. Department of Defense (DOD) funds channeled through the Central Intelligence Agency to train three Cambodian battalions to interdict the Sihanouk Trail before it joined the Ho Chi Minh Trail. Committed to battle in southern Laos on 1 January 1971, one battalion deserted the battlefield, a second one mutinied during training, and a third had to be repurposed after suffering 80 casualties. By late January, the project was temporarily suspended.
Project Copper was revived in March 1971. Lon Non committed his 15 Brigade Infanterie (15 BI) to the task. One battalion of the brigade occupied two minor outposts. The Cambodian troops were recalled for duty near Phnom Penh, with the last of them being repatriated in June 1971. Thus began and ended military cooperation between the two governments.