9. what was the effect of the “christmas bombings” of 1972 on the peace negotiations?

Operation Linebacker II was a US Seventh Air Force and US Navy Task Force 77 aerial bombing campaign, conducted against targets in the Democratic Republic of Vietnam (North Vietnam) during the final period of US involvement in the Vietnam War. The operation was conducted from 18 to 29 December 1972, leading to several informal names such as "The December Raids" and "The Christmas Bombings".[8]Unlike the Operation Rolling Thunder and Operation Linebacker interdiction operations, Linebacker II was to be a "maximum effort" bombing campaign to "destroy major target complexes in the Hanoi and Haiphong areas, which could only be accomplished by B-52s".[9][10] It saw the largest heavy bomber strikes launched by the US Air Force since the end of World War II. Linebacker II was a modified extension of the Operation Linebacker bombings conducted from May to October, when the emphasis of the new campaign shifted to attacks by B-52s rather than smaller tactical fighter aircraft.

 "After intensive negotiations between National Security Adviser Henry Kissinger and North Vietnamese Foreign Minister Le Duc Tho, the two sides reached an agreement in October 1972, and Kissinger announced, “Peace is at hand.” But the South Vietnamese raised objections, and the agreement quickly broke down. An intensive 11-day bombing campaign of Hanoi and other North Vietnamese cities in late December (the “Christmas bombings”) was followed by more negotiations, and a new agreement was finally reached in January 1973 and signed in Paris.