Jeremi Suri in Wired:
On the most obvious level, the mission failed. It may have scared the Soviets, but it did not compel them to end their support for Hanoi, and the North Vietnamese certainly didn't dash to Paris to beg for peace. Nixon and Kissinger believed, though, that their threats opened the door to the arms-control deals of the early '70s. According to this argument, leaders in Moscow recognized after October 1969 that they had better negotiate with Washington, on terms amenable to American interests.That is just part of Wired magazine's Free Month. Free - the new business model.
More than 35 years after Giant Lance, I asked Kissinger about it during a long lunch at the Four Seasons Grill in New York. Why, I asked, did they risk nuclear war back in October 1969? He paused over his salad, surprised that I knew so much about this episode, and measured his words carefully. "Something had to be done," he explained, to back up threats the US had made and to push the Soviets for help in Vietnam. Kissinger had suggested the nuclear maneuvers to give the president more leverage in negotiations. It was an articulation of the game theory he had studied before coming to power. "What were [the Soviets] going to do?" Kissinger said dismissively.