Let's say Stalin takes the "Socialism in One Country" doctrine very much to heart and completely gives up on the traditionally western-looking focus of past Russian Regimes, and instead focuses on developing the interior and hinterlands of the USSR? (Instead of Ukraine, Belarus, Baltics, etc)
1) What areas of central and eastern Russia could be ripe for massive development and industrialization?
2) What effect would this have, economically, leading up to and during WWII?
3) With a proportionally stronger interior economy, could the USSR survive longer?