How Alexandrov disappeared and what happened to him afterward remains unknown, but several theories have been put forward. According to an article in the newsmagazine
Time in October 1985, the leading thoughts on the matter were that "The mystery of his disappearance had been compounded by the suspicions of some Western scientists that the nuclear winter scenario was promoted by Moscow to give antinuclear groups in the U.S. and Europe some fresh ammunition against America's arms buildup"...and that others "speculate that Alexandrov was planning to renounce the nuclear winter concept and may have been kidnapped by the KGB. According to another theory, the physicist defected to the West." A. Levakov suggests that his supercomputer work on nuclear winter was as embarrassing to the Soviet Union as it was to the USA. According to the
Mitrokhin Archive, during a conference in 1987 the head of the
KGB's
First Chief Directorate Vladimir Kryuchkov accused the
CIA's
Deputy Director Robert Gates of kidnapping Alexandrov and holding him against his will.
Andrew Revkin assumes that he was a spy; it was never clear whether for the USSR, U.S., or both. US colleagues regarded his work on nuclear winter computer models to be on the extreme fringe, a position which toed the Soviet
party line at the time – a position that, in private, he reportedly acknowledged was nonsense. US colleagues also pointed to his unorthodox denial by the US visa agency to permit him access to dual-use
supercomputers, a denial which transpired after his name-dropping jokes about how he could freely access the coveted
Cray X-MP at the US nuclear weapons lab
LLNL, and a denial which is likely a key factor in how he could have possibly fallen so far from favor in the Soviet establishment. Someone from Moscow would attempt to "phone"/internet access this powerful US computer a few months before his disappearance. Upon learning of the missing-person case that had not been reported on in Madrid at the time, nuclear winter colleagues, in particular the US team that included
Alan Robock, took a pact not to raise the alarm as they thought it conceivable that he had defected to the West. Robock would later regret taking this pledge as a lost opportunity to find him before the trail went cold. ==See also==