Resource constraints. Idiology is something that mostly is only used when you have the luxury. Most people care more about there own country and they belive the can rule that country.

There was simple no way the USSR could do much for world revolution in 1924 onwards. They had to focus on improving there own conditions.

You cant compare it to predecessor because the theory of world revolution was never really in place as a main policy. They where always more focused on there own country.

Were you looking at this more from an ideological perspective, foreign policy or the economy? They sort of all hinge on each other but they don't share a clear single predecessor policy so I just wanted to clarify.