Litvinov's strategy faced ideological and political obstacles. The ruling Conservatives in Britain, who dominated the House of Commons from 1931 onwards, continued to regard the Soviet Union as no less of a threat than Nazi Germany (some saw the USSR as the greater threat). At the same time, as the Soviet Union underwent upheavals in the midst of the Great Purge of 1934–1940, the West did not perceive it as a potentially valuable ally.[1][2]