More seriously than rogue pigeons, the paucity of intelligence on the Axis Powers essentially led to MI5’s near total collapse. In July 1940, amid the Battle of Britain and the so-called ‘fifth column’ crisis, MI5’s internal bureaucracy completely broke down under the strain of checking reports on supposed enemy agents and other ‘suspicious’ activities, ranging from the plausible to the preposterous. So many reports of ‘enemy spies’ bombarded MI5 that its central Registry, the nerve centre of its operations, which in 1940 contained two million cards and 170,000 ‘personal files’ or dossiers, ground to a halt and then collapsed. The chaos that these reports caused – those on ‘enemy light signalling’ alone reached a stack five feet high in MI5’s office – was made worse by the spectre of events on the Continent. Between May and June 1940 Hitler launched an unprecedented ‘lightning war’ (Blitzkrieg) in Europe, which led to the surrender of European countries from the Netherlands to Norway in quick succession. Hitler’s Blitzkrieg was facilitated by ‘fifth column’ saboteurs and agents planted and parachuted into the invaded countries. With their conventional armies obliterated, the Dutch gave up after just five days of fighting; the Belgians after seventeen. At the end of May the entire British Expeditionary Force (BEF) was evacuated from the Continent at Dunkirk, and by mid-June Britain’s greatest ally in Europe, France, had ignominiously surrendered. Britain was standing alone in Europe, fighting for its survival, with only its empire and Commonwealth to support it. The Joint Intelligence Committee, Britain’s highest overall intelligence assessment body, sombrely planned for its own evacuation from London, and speculated on how it could survive (by hiding in bunkers) after the Nazi invasion of Britain that appeared imminent. The JIC was not fantasising: the German leadership had drawn up detailed plans for an invasion of Britain (codenamed Operation Sealion), which included the arrest and likely execution of a number of senior MI5 and SIS officers, whose names the Gestapo had probably found in London telephone directories and entries in Who’s Who, which in many cases, as we have seen with Sir Eric Holt-Wilson, gave their home addresses.7
The situation for Britain was actually even worse than this suggested. Due to the Nazi–Soviet Pact of August 1939, the Soviet Union and Nazi Germany entered the war as allies. It is often forgotten that the invasion of Poland in September 1939, which brought Britain into the war, was carried out by German and Soviet forces together. For a nightmare period between the outbreak of war in September 1939 and Nazi Germany’s invasion of Russia in June 1941, it appeared that Germany, Italy, Japan and the Soviet Union would act in uneasy concert and divide the spoils of the world between themselves. Britain nearly went to war with the Soviet Union when the Red Army invaded Finland in November 1939, and as papers of the British Chiefs of Staff reveal, in April 1940 the RAF was planning a devastating bombing attack on the Soviet Union, codenamed Operation Pike.8
In these circumstances, with Britain standing alone against Nazi and Soviet forces, in the summer of 1940 MI5 concluded – inaccurately, as it turned out – that large-scale German sabotage and espionage networks were operating in Britain, as they had done in Europe. The truth would only be revealed later: unbeknownst to MI5 at the time, code-breakers at Bletchley Park had in fact identified virtually all German agents operating in Britain. Unaware of this, in June 1940 MI5 took one of the most controversial decisions it would ever take, recommending the mass internment of all ‘enemy aliens’ in Britain. In total over 27,000 foreign nationals were interned in Britain during the war on MI5’s orders. In Britain, as with the wartime internment of Japanese Americans in the United States, this was a lamentable low point in the history of civil liberties.9
Due to its lack of reliable information on Nazi Germany, British intelligence started the Second World War effectively fighting in the dark. To make matters worse, it was chronically under-resourced: in 1939 MI5 had a total staff of only thirty-six officers. The bungling efforts of British intelligence in the early days of the war were symbolised by a catastrophic incident that befell SIS in October 1939, soon after the outbreak of hostilities. Two SIS officers stationed in the Netherlands, Richard Stevens and Sigismund Payne Best, were lured to the town of Venlo on the Dutch–German border on the pretext of meeting a group of anti-Hitler German officers. In reality, the ‘resistance’ group was controlled by the Gestapo. The two SIS officers were immediately arrested, dragged from neutral Dutch territory across the German border, and imprisoned for the rest of the war. Inexplicably, they had come to the rendezvous with a complete list of their agents in Germany, all of whom were promptly arrested and neutralised (with many executed) by the Nazi authorities. In one fatal swoop, Britain’s network of agents in the Third Reich was dismantled.10
The ‘Venlo incident’ seems to have cast a long shadow. Although little information is currently available in British records, it does not seem that after Venlo SIS assisted or sponsored any significant anti-Hitler resistance groups within Germany. This may have been caused by anxiety after Venlo, or it may have been due to fears within Whitehall that killing Hitler would simply create a martyr and unleash further demons. None of the various wartime attempts made on Hitler’s life by German officers, the most famous of which was the ‘July Bomb Plot’ of 1944, appears to have been sponsored by SIS or any other part of British intelligence. Armchair assassins and ‘critical historians’ today rarely comprehend the genuine bravery shown by these plotters, but even with that concession, contrary to what has been suggested in a recent Hollywood film, Operation Valkyrie in July 1944 was not intended to oust Hitler and establish democratic government in Germany. Instead, it was an attempt by a group of German officers to replace the Third Reich with a non-democratic military dictatorship.11
One of the reasons the British secret state had such poor intelligence on Nazi Germany at the start of the war was the extreme difficulty of gaining reliable information on a closed police state like the Third Reich. To this day, understanding its power structures is still one of the most controversial, and voluminous, subjects in modern history. Historians today, equipped with German records, which British intelligence at the time was not, are unable to agree on such basic questions as who was ultimately in charge of Nazi Germany and whether Hitler was a ‘strong dictator’ or a ‘weak dictator’. That said, in the pre-war years British intelligence as a whole failed catastrophically to understand the mindset of the Nazi leadership. There were a few pre-war officers, in particular MI5’s John Curry and Dick White, who grasped the true nature of the strategic threat posed by the Third Reich, but their attempts to convince the rest of Whitehall of this came to little. The Oxford historian and wartime recruit to SIS Hugh Trevor-Roper was shocked to find that none of his colleagues had bothered to read the ‘sacred texts’ of those they were fighting, such as Mein Kampf. To make matters worse, MI5 and SIS had given an overwhelming priority in the pre-war years to Soviet and Comintern activities, and had largely neglected the growing threat of Nazi Germany. This also meant that they viewed the Nazi threat through the paradigm of the Comintern, and erroneously concluded that fascist organisations such as Oswald Mosley’s British Union of Fascists (BUF) were run along similar lines to the British Communist Party, which was controlled by Moscow. In fact the black-shirted members of the BUF were above all British, and contrary to what MI5 believed, were not willing to bow to instructions from Berlin or Rome in the way that the ‘internationalised’ British Communist Party followed instructions from ‘the centre’, Moscow. That said, it is impossible to know exactly how the BUF would have reacted if there had been a Nazi invasion of Britain.12
The remarkable failures of Britain’s intelligence services before the war led them in some astonishing directions during it. By 1942 the intelligence chiefs in Whitehall had become so desperate in their bid to understand the mindset of the Nazi leadership that they employed a water-diviner, nicknamed ‘Smokey Joe’, and a Dutch astrologer, Louis de Wohl, who both claimed that they could predict Adolf Hitler’s behaviour from his star sign (Libra rising). It was only after de Wohl had been employed for several months that MI5 and SIS realised he was nothing more than a con artist.13
One of the main reasons why, despite the meagre intelligence Britain had at the start of hostilities, its intelligence machinery achieved such phenomenal wartime successes was because of Winston Churchill, who, as the world’s leading intelligence historian Christopher Andrew has pointed out, more than any British