This is from a pretty interesting piece by James Marson in the Guardian:

There are three ways that people justify Stalin. First, he was a “successful dictator” in the second world war and the industrialisation drive; second, his record wasn’t as bad as Hitler’s; third, his ideology was more palatable.

The “successful dictator” argument is more or less the line that the Kremlin follows, with its glorification of the victory in the second world war and glossing over of everything else. But it is ahistorical to separate the bad from the good – they are both part of one whole.