The best diaries, such as those of Pepys and Boswell, are spontaneous effusions of the ego; the worst, those written by (say) Field Marshal Haig and President Eisenhower, are calculated exercises in self-justification. The journals of Ivan Maisky (1884–1973), Russian ambassador in London from 1932 to 1943, rank some way down this scale since they were penned for possible perusal by Stalin, whose homicidal suspicions were frequently focused on Soviet representatives abroad.

Yet even under the shadow of the Red Tsar’s axe, Maisky showed remarkable independence, and this chronicle of his embassy before and during the Second World War abounds in interest. It not only sheds fresh light on Anglo-Soviet relations but also contains fascinating accounts of prominent British figures, among them Bernard Shaw, H G Wells, the Webbs, Lloyd George, Eden, Halifax, Chamberlain, Beaverbrook and, above all, Churchill. Moreover, it is full of piquant vignettes: Beatrice Webb asserting that Churchill was not a true Englishman because of his ‘negro blood’; Churchill himself complaining that US army divisions contained battalions of laundrymen, hairdressers and milk sterilisers; Herbert Morrison endeavouring, at one embassy reception, to teach Maisky’s wife, Agniya, to dance the Lambeth Walk.

The diary was unearthed from Russian archives by Gabriel Gorodetsky and it will eventually be published in three volumes with detailed references and full academic apparatus. This book, however, is a largely footnote-free digest with linking contextual passages supplied by Gorodetsky. He deserves all credit for a masterly feat of original research and scholarly exposition, but the taster leaves one longing for the full meal, since there is not the space here to give readers all the guidance they need.

For instance, Maisky records that in 1937 he reassured Churchill, who by then favoured the construction of a ‘grand alliance’ against Nazi Germany, that Stalin’s purges had not undermined the Soviet Union’s fighting capability. According to the diary, Churchill concluded by damning Trotsky and saying, ‘I am definitely in favour of Stalin’s policy. Stalin is creating a strong Russia.’ This questionable conversation requires a gloss, if only to mention that Churchill had recently read a book about Russian collective poultry farming that revealed such ineptitude, squalor and starvation as to indicate that Soviet strength was a mere facade.

Maisky was a revolutionary of Polish-Jewish descent who made the mistake of supporting the Mensheviks in and immediately after 1917. Although he soon recanted, holding various bureaucratic and diplomatic positions in the Bolshevik government, Stalin distrusted him as a bourgeois intellectual and disliked him as a rootless cosmopolitan. But in spite of this, he appointed Maisky, who was an old associate of the foreign minister Maxim Litvinov, as ambassador to London in order to promote the USSR’s new policy of gradualism, pragmatism and collective security at a time when Hitler looked set to establish a Third Reich on the ruins of the Weimar regime. Grappling with this almost insuperable task, Maisky also faced hostility and prejudice in Britain. The Tory MP Chips Channon, whose diary is both more frivolous and more entertaining than Maisky’s, dubbed him ‘the Ambassador of torture, murder and every crime in the calendar’. Neville Chamberlain described Maisky as a ‘revolting but clever little Jew’.

Nevertheless, by deploying wit, charm and pertinacity, as well as by dispensing gifts of caviar and vodka to journalists and others, Maisky established himself as a significant figure on the diplomatic scene. He engineered Anthony Eden’s meeting with Stalin in 1935; although no anti-Nazi coalition eventuated, he claimed in the diary that Eden shared his view that socialism was the wave of the future. Maisky did his best to expose the folly and danger of appeasing Hitler. He damned the coarse, dull-witted Ribbentrop for having ‘the outlook and manners of a Prussian NCO’. He cultivated Churchill, who in 1938 proposed to drink his 1793 bottle of wine with Maisky when ‘Britain and Russia beat Hitler’s Germany’. He made overtures to the pious and platitudinous Lord Halifax and to Chamberlain, whom he thought dry, limited and narrow-minded – an ‘accountant in politics’.

But the British remained unconvinced that Russia would defend Czechoslovakia against German aggression provided that France did the same. And even when Hitler threatened Poland, Maisky found it impossible to galvanise the viscerally anti-communist British government into doing a deal with Stalin. So tardy were the manoeuvres of the Foreign Office that Maisky reckoned it must rely for its mobility on oxen. When he asked Admiral Drax, head of the military mission finally dispatched to Russia in August 1939, why it was going by boat, Drax pursed his lips and said that flying would be uncomfortable: ‘You see, there are nearly 20 of us and a lot of luggage.’

Contrary to the account that appears in Maisky’s memoirs, his diary reveals that the Nazi–Soviet pact took him completely by surprise. He was further shocked when the Red Army invaded Poland, though he loyally maintained in the diary that this was to ‘protect the population’s lives and property’. Until June 1941 he was in a desperate position, ostracised by both Whitehall and the Kremlin, and only kept in London because Stalin feared another Munich. Agniya had already suffered a nervous breakdown and like all Soviet emissaries her husband lived in terror of being recalled to Moscow – in Washington Litvinov nearly went mad and in Rome Boris Shtein was so petrified that his doctor advised him to let off steam by smashing up a dinner service once a month.

After Hitler’s assault on Russia, which Maisky had warned Stalin about only four days before it occurred, the ambassador’s standing in Britain improved. Indeed, as the Red Army bore the brunt of fighting Germany, Stalin’s own appearances on British newsreel screens, Maisky observed, prompted louder cheers than those for Churchill, let alone for the king and queen. Following America’s entry into the war, Maisky spent most of his time trying to dispel mutual mistrust among the Allies while urging the necessity of a second front in northern France. However, instead of heeding this advice, Churchill persuaded Roosevelt to attack Europe’s ‘soft underbelly’, explaining to Maisky (if his account is true) that ‘The Germans wage war better than we do. Especially tank wars … Also we lack the “Russian spirit”: die but don’t surrender!’

Maisky represented his summons home in June 1943 as a protest against the West’s failure to open the second front. In fact, it was an assertion of dictatorial control over the diplomatic corps. Maisky had forged valuable personal relationships in Britain and taken initiatives of his own, often disguising them as the proposals of his contacts. But having first shackled him to an NKVD minder, who even sat in on ambassadorial meetings with Eden, Stalin replaced him with a robotic apparatchik named Gusev, whose sole refrain was ‘I will refer the matter to my superiors.’

Back in Moscow Maisky was initially sidelined. But in 1953 he was arrested, charged with treason and imprisoned in the Lubyanka, where he was interrogated (perhaps being tortured by Beria himself – his own accounts varied) and eventually confessed that Churchill had recruited him as a spy. But Stalin died before he could have Maisky executed. Eventually rehabilitated, the ambassador lived to write another day. He thought of calling his memoirs, which should be taken with even larger grains of salt than the diary, ‘The Novel of My Life’.