The role of ideology in Soviet foreign policy 1917–1941:
Permanent Revolution - belief that Russia’s revolution could not survive in isolation and needed to spread internationaly. to achieve this the revolution must be continuous. This way of thinking affected policy involving the spread of Socialism/Communism.
The United front 1920s - encouraged cooperation with Social Democrats, the idea was to be able to maintain communist independence and ideology, & Use alliances as a stepping stone to revolution. This was a shift from aggressive revolution policy to practical cooperation. This was an attempt to expand communist influence gradually by building trust with the working class, promoting and increasing membership and support and influencing policies over time.
The popular front 1930s - a broad anti-fascist alliance, that encouraged cooperation with socialists, liberals, and the middle-class parties while, ironically, defending the use of democracy, instead of immediate revolution to stop Fascism. The USSR pursued collective security against fascism and in 1934, they joined the League of Nations & signed alliances with western nations.
This part of Soviet forign policy was about the safety of the USSR & stopping Fascism, rather than spreading communism like the earlier policy.