One must expect a war between U.S.A. and U.S.S.R. which will begin with the total destruction of London. I think the war will last 30 years, and leave a world without civilised people, from which everything will have to build afresh - a process taking (say) 500 years.
Letter to Gamel Brenan (September 1, 1945), "The Selected Letters of Bertrand Russell" edited by Nicholas Griffin, (p. 410), 2002.
