Colby, who was head of the CIA's Far East Division, pleaded to Harriman to allow the resumption of air shipments. "My arguments became more forceful," Colby recalled, "reflecting the intense cables I was receiving from the two CIA officers who were still up in the hills observing and reporting on what was happening." Harriman reluctantly approved an Air America arms drop—along with instructions that it is used for purely defensive purposes. Further shipments followed. As Colby pointed out, however, Harriman personally approved "each and every clandestine supply flight and its cargo." As Hanoi sent additional troops into Laos during 1963, the Kennedy administration authorized the CIA to increase the size of the Hmong army, now headquartered in the valley of Long Tieng. By the end of the year, a reported 20,000 Hmong were armed. They acted as guerrillas, blowing up NVA supply depots, ambushing trucks, mining roads, and generally harassing the stronger enemy force. Air America again took a greater role in the slowly expanding conflict. Laos 1964 In 1964 marked the initially limited employment of U.S.-Thailand and Laos operations. The United States believed that because there was more communist activity in Laos, it threatened South Vietnam. The Royal Laotian Air Force (RLAF) began to receive increased support from the United States. Counterinsurgency training, assisting cooperation, and logistical support were some of the types of aids provided at this time. The RLAF saw an additional endowment of resources from the US after a failed right-wing attempted coup catalyzed a resurrection of Pathet Lao onslaughts on rightists and neutralists in the Plaines des Jarres. Full-scale fighting broke out in Laos in March 1964 when North Vietnamese and Pathet Lao forces attacked across the Plaines des Jarres. In mid-May the communists had taken control of the strategic region. Ordnance was also released shortly thereafter, so the RLAF could strike the communists. Because the airstrikes only allowed to be performed by the RLAF, at the request of the U.S. ambassador in Vientianne, the RLAF received seven T-28s loaned temporarily by the U.S. On 20 May, an additional 10 T/RT-28 were loaned by South Vietnam to the RLAF. At this time, the U.S. Joint Chief of Staff agreed to send three C-47 to train the RLAF pilots. The C-47s and 21 personnel arrived in Ubon on 24 July and immediately started to train the Laotian air and ground crew. In January 1964, the CIA