Editing South Vietnam (section)

===1973–1975===
In accordance with the [[Paris Peace Accords]] signed on 27 January 1973, US military forces withdrew from South Vietnam at the end of March 1973 while PAVN forces in the South were permitted to remain in place.

North Vietnamese leaders had expected that the ceasefire terms would favour their side. As Saigon began to roll back the Việt Cộng, they found it necessary to adopt a new strategy, hammered out at a series of meetings in Hanoi in March 1973, according to the memoirs of [[Trần Văn Trà]]. As the Việt Cộng's top commander, Trà participated in several of these meetings. A plan to improve logistics was prepared so that the PAVN would be able to launch a massive invasion of the South, projected for 1976. A gas pipeline would be built from North Vietnam to the Việt Cộng provisional capital in [[Lộc Ninh, Bình Phước|Lộc Ninh]], about {{cvt|60|mi|km}} north of Saigon.

On 15 March 1973, Nixon implied that the US would intervene militarily if the communist side violated the ceasefire. Public reaction was unfavorable, and on 4 June 1973 the [[US Senate]] passed the [[Case–Church Amendment]] to prohibit such intervention. The [[1973 oil crisis|oil price shock of October 1973]] caused significant damage to the South Vietnamese economy. A spokesman for Thiệu admitted in a TV interview that the government was being "overwhelmed" by the inflation caused by the oil shock, while an American businessman living in Saigon stated after the oil shock that attempting to make money in South Vietnam was "like making love to a corpse".<ref>{{Cite book |last=Cooper |first=Andrew Scott |title=The Oil Kings: How the U.S., Iran, and Saudi Arabia Changed the Balance of Power in the Middle East |date=2011 |publisher=Simon & Schuster |location=New York |page=205 |language=en}}</ref> One consequence of the inflation was the South Vietnamese government had increasing difficulty in paying its soldiers and imposed restrictions on fuel and munition usage.

After two clashes that left 55 South Vietnamese soldiers dead, President Thiệu announced on 4 January 1974 that the war had restarted and that the Paris Peace Accord was no longer in effect. There were over 25,000 South Vietnamese casualties during the ceasefire period.<ref>{{Cite web |title=This Day in History 1974: Thieu announces war has resumed |url=http://www.history.com/this-day-in-history.do?action=Article&id=1592 |archive-url=https://web.archive.org/web/20090225151920/http://www.history.com/this-day-in-history.do?action=Article&id=1592 |archive-date=25 February 2009}}</ref> The same month, China attacked South Vietnamese forces in the [[Battle of the Paracel Islands|Paracel Islands]], taking control of the islands.

In August 1974, Nixon was forced to resign as a result of the [[Watergate scandal]], and the [[US Congress]] voted to reduce assistance to South Vietnam from $1&nbsp;billion a year to $700&nbsp;million. By this time, the Ho Chi Minh trail, once an arduous mountain trek, had been upgraded into a drivable highway with gasoline stations.

In December 1974, the PAVN [[Battle of Phước Long|launched an invasion at Phuoc Long]] to test the South Vietnamese combat strength and political will and whether the US would respond militarily. With no US military assistance forthcoming, the ARVN were unable to hold and the PAVN successfully captured many of the districts around the provincial capital of Phuoc Long, weakening ARVN resistance in stronghold areas. President Thiệu later abandoned Phuoc Long in early January 1975. As a result, Phuoc Long was the first provincial capital to fall to the PAVN.<ref>{{Cite book |last=Conboy |first=Kenneth |url=https://books.google.com/books?id=cyvDCwAAQBAJ&q=Phuoc+Long+and+PAVN&pg=PT49 |title=The NVA and Viet Cong |date=2012 |publisher=Bloomsbury Publishing |isbn=978-1-78096-766-0 |language=en |access-date=11 June 2021 |archive-date=12 June 2021 |archive-url=https://web.archive.org/web/20210612055546/https://books.google.com/books?id=cyvDCwAAQBAJ&q=Phuoc+Long+and+PAVN&pg=PT49 |url-status=live}}</ref>

In 1975, the PAVN launched an [[Battle of Ban Me Thuot|offensive at Ban Me Thuot]] in the [[Central Highlands (Vietnam)|Central Highlands]], in the first phase of what became known as the [[Ho Chi Minh Campaign]]. The South Vietnamese unsuccessfully attempted a defence and counterattack but had few reserve forces, as well as a shortage of spare parts and ammunition. As a consequence, Thiệu ordered a withdrawal of key army units from the Central Highlands, which exacerbated an already perilous military situation and undermined the confidence of the ARVN soldiers in their leadership. The retreat became a rout exacerbated by poor planning and conflicting orders from Thiệu. PAVN forces also attacked south and from sanctuaries in Laos and Cambodia [[Hue–Da Nang Campaign|capturing Huế and Da Nang]] and advanced southwards. As the military situation deteriorated, ARVN troops began deserting. By early April, the PAVN had overrun almost 3/5th of the South.

Thiệu requested aid from US President [[Gerald Ford]], but the US Senate would not release extra money to provide aid to South Vietnam, and had already passed laws to prevent further involvement in Vietnam. In desperation, Thiệu recalled Kỳ from retirement as a military commander, but resisted calls to name his old rival prime minister.