Clearly this paid off

tell that to the hundreds of thousands of soviets captured & killed in the reoccupied territory after neither the Stalin or Molotov defensive lines were functional because they moved the border. on paper it makes sense why they took territories closer to the Axis in preparation for war but it didn't actually translate into a better defensive strategy when war broke out. less prepared and farther-to-supply troops were fed to the germans who still advanced at breakneck speed & had to be stopped by millions of new mobilized personnel.

those troops should not have been lost so easily or quickly and would've made better accounts of themselves if not for a flawed strategic model & breathtaking soviet confidence/arrogance in the expected duration of the nonaggression pact