How about I just take out the statements from each the sentence?  

 From: 
 *"Others have acknowledged that despite its inertia and repression (though very mild relative to the Stalin years), the Brezhnev era did offer a relative prosperity to a populace and leadership battered by decades of war, famine, collectivisation and crash industrialisation, deadly political crises, arbitrary mass murder and arrest, and the volatility of the Khrushchev years." 
 To: 
 *"Others have acknowledged that despite its inertia and repression (though very mild relative to the Stalin years), the Brezhnev era did offer a relative prosperity to a populace and leadership battered by decades of war, famine, collectivisation and crash industrialisation, deadly political crises, and the volatility of the Khrushchev years." 

 From: 
 *"However, the Stalinist system was probably beyond repair, and the Gorbachev reforms started in motion forces of change that demonstrated that meaningful reform would eventually threaten Communist Party hegemony." 
 To: 
 *"However, the Gorbachev reforms started in motion forces of change that demonstrated that meaningful reform would eventually threaten Communist Party hegemony."