Henry Kissinger and Lê Đức Thọ had respectively been the United States and North Vietnamese representatives at discussions beginning in 1968 in Paris, France which aimed to put an end to the Vietnam War.

[5] However, the agreement was not ratified by the United States Senate, and fighting restarted before American soldiers left the country.

Controversy focused on his role in orchestrating the secret bombing of Cambodia, as well as his involvement in planning or aiding events that were deemed antithetical to the principles of the Peace Prize, such as Operation Condor, the Bangladesh Liberation War, and just a month earlier, the 1973 Chilean coup d'état.

The New York Times published an editorial dubbing it the "Nobel War Prize", describing the award as "at the very least, premature".

[16] In a joint letter to the Norwegian Parliament, multiple Harvard professors wrote that awarding Kissinger and Thọ was "more than a person with a normal sense of justice can take".

"[7] Thọ, in turn, did decline the prize, stating that "such bourgeois sentimentalities" were not for him, and citing the fact that the Paris Peace Accords had not yet stopped the fighting in Vietnam,[7] though he said he would consider accepting the prize if the Paris Accord "is respected, the arms are silenced and real peace is established in South Vietnam".

[3][7] Aase Lionaes, the chairwoman of the 1973 Nobel Committee, gave the award ceremony speech, stating In awarding the Prize in 1973 as well to two responsible politicians at the centre of events, the Nobel Committee of the Norwegian Storting emphasizes its belief that the approach to a solution of the many controversies that have led to or may lead to war must be via negotiations, not through total war aiming at total victory.

[8]Kissinger received half of the allotted prize pool for 1973, roughly $65,000 (equivalent to $446,000 in 2023), which he used to set up a scholarship fund in the name of his parents for the children of dead or missing American servicemen.

On 1 May, the day after Saigon fell, Kissinger tried to give back the prize, stating via a cable to the Nobel Committee that "I regret, more profoundly than I can ever express, the necessity for this letter... the peace we sought through negotiations has been overturned by force.

[24][25] On 11 January 2023, documents from the 1973 nomination process were unsealed, showing that even the members of the committee who voted for Kissinger and Thọ believed that they could prove to be poor choices; further, they were skeptical that the Paris Accords would bring lasting peace.

[21] Stein Tønnesson, a Norwegian historian who reviewed the documents, said of them "I am even more surprised than I was at the time that the committee could come to such a bad decision.