The failure of governments to gauge Hitler's intentions in the 1930s taught all the major powers two crucially important lessons: 'know your enemy' and 'be prepared'. The huge investment in resources and manpower that was devoted throughout the Cold War to the collection and evaluation of Intelligence, in order to apply those lessons and avoid the same mistake, was matched by the scale of the arms race. But in the 1930s, it was not only Hitler's intentions that western policy makers could not agree on. Whether to make common cause with the Soviet Union against the perceived threat from Germany was not a straightforward issue for British policy makers, either.
From the time of the Bolshevik Revolution, Soviet foreign policy had been driven by the twin engines of, on the one hand, World Revolution, financed and promoted by the Soviet regime through the Communist International and, on the other, national self-interest, as practised by the diplomatic efforts of the Soviet foreign ministry. This duality of goals was echoed in western opinion. Communists, fellow-travellers, large sections of the trade union movement and a significant number of left-leaning and liberal intellectuals saw the Soviet regime as the first attempt to administer a country and manage an economy in the interests of the workers, rather than for the profits of bankers and industrialists. Believing that the Soviet state was committed to building an equal and just society, and comparing what they believed to be its achievements with the West, which was mired in depression, reeling from the triumph of Fascism in Spain, and fearing the worst from Hitler, the Left's preference was a more readily understood option at the time than it might seem today.
For the Chamberlain government and its officials, however, there was little doubt about the nature of the Soviet regime. From the early 1930s reports from British diplomats in the USSR were both informative and perceptive. From open sources-covert western intelligence operations inside the USSR being negligible at that time-