When the Berlin Wall came down November 9, 1989, the decades-long division of Europe was over. But there was another event, just two weeks before, that also broke down barriers and changed the course of the Cold War. In the last week of October, the director of the Soviet All-Union Institute of Ultra-Pure Biological Preparations, Vladimir Pasechnik, was on a business trip to France. He used a phone booth in Paris to call the British Embassy and offered to defect. The British Secret Intelligence Service responded with alacrity, and Pasechnik was soon on his way to London. Over the course of several months, Pasechnik was debriefed at a safe house on the coast of England. The British were astounded at what he told them.Western intelligence agencies had long puzzled over whether the Soviets possessed a biological weapons program, but they lacked solid proof. Moreover, for many years, there had been debate among policy and intelligence analysts in the West about whether biological weapons made sense in the nuclear age. The thinking was that nuclear weapons were such an effective deterrent that germ warfare wasn't worth the investment. President Richard Nixon reflected this outlook when he decided in 1969 to abandon the U.S. offensive germ warfare program. "We'll never use the damn germs, so what good is biological warfare as a deterrent?" Nixon told his speechwriter William Safire. "If somebody uses germs on us, we'll nuke 'em." The assumption was that the Soviet Union had reached a similar conclusion.