On 27 January 1973, all the protagonists in the protracted Vietnam conflict, the Ten Thousand Day War, agreed to end hostilities, and signed the Paris Accords. That did not stop the fighting.
On this day 50 years ago, the United States, the northern Democratic Republic of Vietnam, the Revolutionary Viet Cong Government and the US-backed Republic of Vietnam signed the Paris Accords in the French capital, calling for a ceasefire and the restoration of peace in Vietnam.
This was the final phase of negotiations that began on 13 May 1968 led by Le Duc Tho, special adviser to the North Vietnamese communist regime, and US National Security Adviser, Henry Kissinger.
The Paris deal was, however, just the beginning of a rocky road towards peace.
Despite the signing of the agreement, fighting between the Viet Cong and Saigon continued on a daily basis.
Superficial support for Saigon
The Paris package included a moderate political solution allowing South Vietnamese President Nguyen Van Thieu to retain power; it recognised the legitimacy of the revolutionary Viet Cong government; it provided for the withdrawal of US troops and the exchange of prisoners of war.
But there was no mention of the withdrawal of troops from North Vietnam.
The Vietnamese communists wanted to bring an end to American occupation and reunite the country, which was divided in 1954 following the Geneva Accords.
Washington wanted to withdraw US troops, release prisoners of war and above all - according to some historians - obtain a "reasonable time" between the departure of the Americans and the fall of the Saigon regime.
Negotiations after the fighting
The negotiations began strongly for the Vietnamese communists in the wake of the Tet offensive in 1968, a massive military triumph despite heavy human losses.
Some 80,000 fighters almost simultaneously carried out attacks in more than a hundred cities in Vietnam, including Saigon, the capital of the south.
By then, US protests in support of calls for the withdrawal of American troops had reached fever pitch.
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At the time, there were two distinct approaches to diplomacy: the official negotiations that took place on Avenue Kleber in Paris, and the secret negotiations between Le Duc Tho and Henry Kissinger, held at several locations outside the French capital.
The Paris Accords evolved in two stages.
The first - between May and October 1968 - consisted of bilateral meetings between Kissinger and Le Duc Tho.
For the Viet Cong, the objective was to stop American bombings of North Vietnam.
The second stage - from January 1969 to 27 January 1973 - focused on the withdrawal of US troops and the political situation in Vietnam.
The end of this second stage was marked by the participation of two other protagonists: the Saigon-based Republic of Vietnam and the Southern Revolutionary Viet Cong Government.
US president Nixon and Kissinger had long believed that military superiority would pressure North Vietnam to seek a peace agreement that was acceptable to the United States.
Whenever the negotiations reached an impasse, Kissinger pushed for military escalation.
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In April 1970, American and South Vietnamese soldiers entered Cambodia with the aim of blocking the Ho Chi Minh Trail - the main supply route from the north to the Viet Cong forces in the south.
But the effort failed.
In October 1970, Nixon proposed a cease-fire and the end of American bombing over Vietnam, Laos and Cambodia as a basis for a peace conference allowing the withdrawal of American troops from the region.
However, North Vietnam refused and demanded the departure of South Vietnam's president Nguyen Van Thieu.
At the end of 1970, Kissinger proposed the opening of a new military offensive in Laos: the "Lam Son 719" operation.
Following two years of intense bombing, conflict and unsuccessful talks, the United States had to revise its objectives in Vietnam. The best that could be hoped for was a sufficiently long period of time between the withdrawal of American troops and the collapse of the government in Saigon - a collapse that appeared inevitable.
The end game
At the end of March 1972, the Viet Cong launched the "Eastertide" offensive.
The relative failure of the campaign and the near certainty of Nixon's re-election weighed heavily on the North Vietnamese decision to resume negotiations with the United States.
The negotiations between Kissinger and Le Duc Tho, which resumed on 20 November 1972, reached an impasse.
Kissinger proposed modifications to the text. In response, Le Duc Tho also presented his own.
The talks stalled on 13 December.
Then, on the 18 December, the United States launched a massive eleven-day bombing campaign to force North Vietnam back to the negotiating table and send a message to President Thieu that he would not be offered a better deal than the one reached in October.
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On 26 December 1972, North Vietnam told the US that it was ready to return to the negotiating table if Washington stopped the bombings.
The talks resumed on 3 January 1973 and ten days later, the sides reached an agreement that included the main points of the October 1972 draft.
Kissinger and Le Duc Tho initialed the agreements on 23 January and four days later the four parties signed at the Centre des conferences internationales, avenue Kleber, in Paris.
Despite the signing, all the protagonists in the conflict knew that the war would continue.
According to recently published documents, the Nobel Peace Prize Committee in 1973 decided to award its prize to Henry Kissinger and Le Duc Tho (who refused the award), knowing full well that the Paris Agreements would not bring peace to Vietnam.
Two years later, on 30 April 1975, the Viet Cong entered Saigon, the southern regime fell and Vietnam was reunified.