In the first half of 1975, the government of the Republic of Vietnam was in deep political turmoil, which reflected the military situation on the battlefield. At least two assassination attempts specifically targeting President Thiệu were foiled. On 23 January an ARVN officer tried to shoot Thiệu with his pistol but failed. The officer was subsequently tried by a military court. On 4 April a Republic of Vietnam Air Force (RVNAF) pilot Nguyen Thanh Trung bombed the Independence Palace with his F-5 Tiger. It later turned out that the pilot had been an undercover member of the Viet Cong since 1969. Following those failed assassination attempts, Thiệu grew suspicious of his own military commanders.