Phnom Penh fell to the Khmer Rouge and the US did nothing for their former ally. On 21 April 1975, Thiệu, under intense political pressure, resigned as president when his closest domestic allies began losing confidence over his handling of the war. In his televised farewell speech, Thiệu admitted, for the first time, having ordered the evacuation of the Central Highlands and the north that led to debacle. He then stated that it was the inevitable course of action in the situation – but also insisted it was the generals who failed him. He went on to excoriate the U.S., attacking "our great ally...the leader of the free world ... The United States has not respected its promises" he declared "It is inhumane. It is not trustworthy. It is irresponsible. Immediately following the speech, the presidency was handed over to Vice President Trần Văn Hương. At his new forward command post at Ben Cat, General Dũng prepared plans for the final battle. He encircled Saigon with four PAVN corps and the hastily assembled 232nd Tactical Force, a total of 19 divisions plus supporting artillery and armored units, approximately 130,000 men. His plan was to avoid intensive street fighting within the city itself by first tying down outlying South Vietnamese forces in their defensive positions and then launching five spearheads through them into the city, each of which had a specific target: the Independence Palace, the Joint General Staff headquarters, the National Police headquarters, Tan Son Nhut Air Base and the Special Capital Zone headquarters. The attacks on the periphery began on 26 April and the main attack on the city center began the following day. After Thiệu's resignation, the South Vietnamese military situation increasingly declined. On the 26th, the PAVN launched an all-out attack to take Biên Hòa and the sprawling logistical complex at Long Binh from the south and southeast. Three days later, the port city of Vũng Tàu was under assault and the pressure against the Cu Chi front was intense. The same disorganization, loss of control, and anarchy that befell I and II Corps now took place in Saigon, where martial law was imposed to control the chaos and lawlessness. Although contemplation of a communist victory by that time had created severe shock in many parts of South Vietnamese society, most did little or nothing to forestall it. A repeat of the Massacre at Huế, albeit on