Final answer:
Secret talks carried out by Robert McNamara, Henry Kissinger, Daniel Ellsberg, and Le Duc Tho played a crucial role outside the formal peace talks in Paris.
Step-by-step explanation:
The subject of this question is History.
Outside the formal peace talks in Paris, secret talks were carried out by Robert McNamara, Henry Kissinger, Daniel Ellsberg, and Le Duc Tho.
These secret talks played a crucial role in the negotiations that led to the signing of the Paris Peace Accords in 1973, which aimed to end the conflict in Vietnam.
Learn more about Secret talks in the Vietnam War