However , behind the scenes , Kampuchean leaders continued to fear what they perceived Coming_to_believe as Vietnamese expansionism .

Shocked by the Kampuchean assault Attack , Vietnam launched Process_start a retaliatory strike Attack at the end of 1977 in an attempt to force the Kampuchean government to negotiate Communication .

Shocked by the Kampuchean assault Attack , Vietnam launched Process_start a retaliatory strike Attack at the end of 1977 in an attempt to force the Kampuchean government to negotiate Communication .

On 25 December 1978 , 150,000 Vietnamese troops invaded Attack Democratic Kampuchea and overran Destroying the Kampuchean Revolutionary Army in just two weeks , thereby ending Process_end the excesses of Pol Pot 's regime , which had been responsible for the deaths Death of almost a quarter of all Cambodians between 1975 and December 1978 .