so Vietnam could exercise its influence through him. However, the events which developed over the next few months would prove Lê Duẩn had been mistaken in his assessment of Nuon Chea. Meanwhile, in Phnom Penh, the Kampuchean leadership had developed a fear and hatred of the Vietnamese leadership as a result of Vietnam's historical dominance over their country. From the Kampuchean perspective, the Vietnamese strategy to dominate Indochina involved infiltrating the communist parties of Kampuchea and Laos with Vietnamese-trained cadres. For that reason, when the first group of North Vietnamese-trained Khmer Rouge personnel returned to the country, they were immediately purged from the KCP. During the months following the defeat of the Lon Nol government, Pol Pot continued to purge the KCP and the Government of Democratic Kampuchea of those who he believed to be Soviet and Vietnamese agents. Then, in the context of the triumphalism that prevailed among the Khmer Rouge leadership—they claimed they had single-handedly defeated the "American imperialists"—Democratic Kampuchea began preparing for war against Vietnam. As the KRA made preparations for its war against Vietnam, state-controlled media in Vietnam sent congratulatory messages to the Government of the Democratic Kampuchea on the second anniversary of its establishment, on 17 April 1977. On 30 April 1977, the second anniversary of the fall of Saigon, the Kampuchean reply came in the form of a military attack against the Vietnamese provinces of An Giang and Châu Đốc, killing hundreds of Vietnamese civilians. The PAVN responded by moving its troops to areas attacked by Kampuchea and, on 7 June 1977, Vietnam proposed high-level talks to discuss outstanding issues. On 18 June 1977, the Kampuchean Government replied by demanding that Vietnam remove all of its military units from the disputed areas, and create a demilitarised zone between the opposing forces. Both sides ignored each other's proposals, and the KRA continued sending soldiers across the border to attack Vietnamese towns and villages. In September 1977, KRA artillery struck several Vietnamese villages along the border, and six villages in Đồng Tháp Province were overrun by Kampuchean infantry. Shortly afterwards, six divisions of the KRA advanced about into Tay Ninh Province, where they killed more than 1,000 Vietnamese civilians in Tân Biên district. Angered by the scale of Kampuchean assaults, the PAVN assembled eight divisions, estimated at around 60,000 soldiers, to launch a retaliatory strike against Kampuchea. On 16 December 1977, the PAVN divisions, with support