With the arrival of the Thai artillery battery in Moung Soui, Operation Triangle set off on 19 July 1964, under the nominal head of General Kouprasith Abhay, who had by now replaced General Phoumi as the Americans’ favourite Laotian General. The Operation ended ten days later with great satisfaction to the Americans, the Laotians and the Thais.
Caught by surprise, the Lao Viet retreated, and the RLG forces were able to retake the key crossroads on the PDJ. Furthermore, not only was Muong Soui saved, but the neutralist forces captured 13 Lao Viet prisoners. Two Lao Viet were killed and ten wounded. No SR artillerymen suffered any casualties, and the neutralist forces lost only one soldier.
Firefly pilots and SR artillerymen made a significant contribution to the success of Operation Triangle.65 President Johnson personally expressed his deep appreciation for
the role of the Thai pilots and artillerymen to Thailand’s Deputy Premier, General
Prapart Charusathien, who was in Washington at the time.