In Saigon, the ally of the Americans, Nguyen Van Thieu, refused to sign it. Under orders from President Nixon, Kissinger was to resume his secret negotiations in October 1972 with his North Vietnamese counterpart, offering him amendments he could not accept. In mid-December, negotiations were suspended and Le Duc Tho returned to Hanoi. Two hours later, North Vietnam and its capital Hanoi suffered a spate of bombings. The air strikes, including bombings from around a hundred B-52s, lasted twelve days. Nixon had warned: "We must punish the enemy in ways that he will really hurt ". How to understand this final act of "cruelty ", this massive and destructive air offensive, when peace was signed just three weeks later? Supported by previously unaired archives, this film plunges us into the heart of the secret negotiations, finally shedding light on the obscure logic of US action, and reveals the extent of the tragedy: even when peace had become the main objective of all players, each player had to show their determination to continue the war.