in Dresden the militants presented Putin with a list of weapons that were later delivered to the RAF in West Germany. Klaus Zuchold, who claimed to be recruited by Putin, said that Putin handled a neo-Nazi, Rainer Sonntag, and attempted to recruit an author of a study on poisons. Putin reportedly met Germans to be recruited for wireless communications affairs together with an interpreter. He was involved in wireless communications technologies in South-East Asia due to trips of German engineers, recruited by him, there and to the West. According to Putin's official biography, during the fall of the Berlin Wall that began on 9 November 1989, he saved the files of the Soviet Cultural Center (House of Friendship) and of the KGB villa in Dresden for the official authorities of the would-be united Germany to prevent demonstrators, including KGB and Stasi agents, from obtaining and destroying them. He then supposedly burnt only the KGB files, in a few hours, but saved the archives of the Soviet Cultural Center for the German authorities. Nothing is told about the selection criteria during this burning; for example, concerning Stasi files or about files of other agencies of the German Democratic Republic or of the USSR. He explained that many documents were left to Germany only because the furnace burst but many documents of the KGB villa were sent to Moscow. After the collapse of the Communist East German government, Putin was to resign from active KGB service because of suspicions aroused regarding his loyalty during demonstrations in Dresden and earlier, though the KGB and the Soviet Army still operated in eastern Germany. He returned to Leningrad in early 1990 as a member of the "active reserves", where he worked for about three months with the International Affairs section of Leningrad State University, reporting to Vice-Rector Yuriy Molchanov, while working on his doctoral dissertation. There, he looked for new KGB recruits, watched the student body, and renewed his friendship with his former professor, Anatoly Sobchak, soon to be the Mayor of Leningrad. Putin claims that he resigned with the rank of lieutenant colonel on 20 August 1991, on the second day of the 1991 Soviet coup d'état attempt against the Soviet President Mikhail Gorbachev. Putin said: "As soon as the coup began, I immediately decided which side I was on", although he noted that the choice was hard because he had spent the best