"When Philby arrived in Moscow in 1963 he had never before actually visited the Soviet Union. It may well have been a brutal shock, however much his Soviet comrades may have hinted at the grim reality of life there and the perversion of the ideal for which he had risked his life. When I was a correspondent in Moscow in the 1980s, I could not but notice how fast even the most committed Western Communists were overwhelmed, once they had spent a few weeks there, by the dismal truth."
Xan Smiley, "Kim Philby: still an enigma," New York review of books 61, no. 19 (December 4, 2014): 46 (45-46).