Misdefending the Realm: How MI5's incompetence enabled Communist Subversion of Britain's Institutions during the Nazi-Soviet Pact

It is well known that the Soviet Union successfully infiltrated the UK government in the years leading up to WW2, but until now, not quite how. Exploiting recently declassified material, Antony Percy here reveals how the USSR caught up so swiftly with Western expertise and weaponry, and so played such a commanding role in the Cold War.