I wrote to some extent about Mussolini's relations with his past here.

As to his specific attitude towards the Soviet Union, there is no special reason he would have considered it to represent any past of significant sentimental value to him. Not only, in Mussolini's mind, attachment to the past was far from a positive trait in a Great Man, but - already in his criticism of the socialist position, during 1917-18, and in 1918-19, with his explicit rejection of Bolshevism - his view, albeit across varying contingent shades, was that the Great War had marked the end of socialism, of Marxism and of all those things which he described in a famous leading column as "bric-a-brac from before the war".

If, in 1914-15, Mussolini's criticism of the socialist leadership was based largely on their contingent failure to transform the great event of the war into a revolutionary event, by the end of the Great War, he had accepted in good measure the idea that the Great War itself had been the true revolutionary event, and that the leading elites (including the proletarian ones), should acknowledge that the revolution they had dreamt of conjuring out of Marxism had not only been set in motion, but for the most part accomplished, by forces which had nothing to do with Marxism, revolutionary socialism or reformism. In other words, at the end of the Great War "socialism is dead, and Bolshevism is the proof that it's gone for good".

When he was informed that Hitler had ordered the execution of Barbarossa, Mussolini - who had a few private recriminations to share with his lover and intimate circle - showed little hesitation in joining. And indeed seemed to regard it as a significant opportunity to restore the Italian stature after the failures in Greece and North-Africa and the very limited impact of his botched offensive in France, by committing a large number of troops to the remote and strategically irrelevant (in so far as the Italian aspirations went) Eastern front. It was only during the second half of 1942, that his recriminations with the German military, and political to a lesser degree, leadership start to surface more frequently, as the war - and internal consensus - became to take a turn for worse. They still remained practical recriminations, though. And there is no particular evidence, that I know of, of Mussolini ascribing any sentimental value to Stalin's regime, which was, at best, another enemy nation, and, at worst, the complete expression of what he had branded twenty five years before as "a travesty of socialism".