You could see the disarmament of the partisans as a pragmatic measure by someone who understood that he would have no chance of winning a civil war in a country where a majority was non-communist and which had a large American troop presence.  The PCI of the seventies and eighties was not that of the initial postwar period; Berlinguer was not Togliatti. I would have found the prospect of them winning power worrying, but not terrifying. Call it the difference between a straightforward fascist party led by a former senior fascist official winning power, and a reformed one which retained a fascist minority and was led by someone who had been a fascist supporter but since then clearly denounced fascism - e.g. like today's Fini.