71. Editorial Note
On June 25, Premier Sim Var charged in a proclamation that South Vietnamese troops had penetrated at least 4.3 miles into northeastern Cambodia on June 18, occupying the town of Phak Nhay. Sim Var also stated that Vietnamese troops continued to occupy Cambodian territory and were organizing for a deeper attack into Cambodia. The South Vietnamese Government claimed no knowledge of this incident and requested information from local authorities in the [Page 231] remote and sparsely populated area of South Vietnam contiguous to the Cambodian border where the incident occurred. The Embassy reported that Sim Var had appealed to the United States to intervene and obtain the withdrawal of Vietnamese troops. If U.S. help was not forthcoming, Sim Var threatened to appeal to other friendly powers, possibly even China.
According to the Embassy in Phnom Penh, the Cambodians appeared dangerously excited and Sim Var, whose government had been defeated on June 21 on a vote on rice imports and frontier relations with Thailand and Burma, was perhaps using the alleged Vietnamese threat as a means of regaining lost face. As the Director of Intelligence and Research, Hugh S. Cumming, Jr., informed Secretary Herter, Vietnamese-Cambodian relations had deteriorated seriously in recent weeks and the border area, never clearly delimited, had seen recent previous incidents. (Memorandum from Cumming to Herter, June 25; Department of State, INR Files: Lot 58 D 776, 1957–58 Intelligence Notes; included in the microfiche supplement)
In a memorandum to Assistant Secretary of Defense for International Security Affairs John N. Irwin II, June 26, the Regional Director of ISA stated that the June 25 incident appeared to be caused by a raid by Viet Cong from Cambodia to rescue a group of prisoners held in South Vietnam. The raiders released 92 prisoners and returned with them to Cambodia with South Vietnamese troops. The Vietnamese did not make contact with the raiders, but they probably crossed the ill-defined border. Regional Director Captain B.A. Robbins suggested that “it was most unlikely that Viet-Nam has consciously invaded Cambodia for should this happen Cambodia would be overrun in about 72 hours.” (Washington National Records Center, OSD/ISA Files: FRC 62 A 1698, 092 Cambodia; included in the microfiche supplement)