Through intrigue, Thảo also helped destabilise and ultimately unseat two South Vietnamese regimes—Diem's and the military junta of Khánh. As the Diệm regime began to unravel in 1963, Thảo was one of the officers planning a coup. His plot was ultimately integrated into the successful plot and his activities promoted infighting which weakened the government and distracted the military from fighting the Viet Cong insurgency. Throughout 1964 and 1965, as South Vietnam was struggling to establish a stable state after the ouster of Diệm, Thảo was involved in several intrigues and coup plots which diverted the government from implementing its programs. In 1965, he went into hiding after a failed attempt to seize power from Khánh and was sentenced to death "in absentia". Although this coup also failed, the subsequent chaos forced Khánh's junta to collapse. Thảo died the same year he was forced into hiding; it is believed that he was murdered after a bounty was placed on his head. After Vietnam was reunified at the end of the Vietnam War, the victorious communists claimed Thảo as one of their own and posthumously made him a one-star general.