There's also the possibility of a Soviet coup that would create a one party Soviet satellite state, like what the Soviets did to Czechoslovakia, which would bring the Iron Curtain to the French border.
How could there be a "Soviet coup" in Italy? In Czechoslovakia, the Communists controlled the Prime Ministership, the Ministry of the Interior, the Ministry of Defense... A totally different situation from Italy. Moreover, the US had pretty much written off Czechoslovakia. According to John O. Crane and Sylvia Crane, Truman had told Jan Masaryk in 1947 during the latter's last visit to the United States, that in case of a crisis, "Czechoslovakia could not count on more than the moral support of the United States." *Czechoslovakia: Anvil of the Cold War*, p. 310. (The authors seem to be basing this on what Masaryk told them in New York in late 1947.) Assuming this is true, word probably got around to Stalin. Even if it didn't, he could probably surmise this. Again, this was totally different from the situation with Italy, where the US went all-out to prevent a Communist victory in 1948.
Or do you mean that there could have been a Czechoslovak-style coup if the Popular Democratic Front (Communists and Nenni Socialists) had won the 1948 election? But it was not remotely close: 48.51 percent for the Christian Democrats, 30.98 percent for the Popular Democratic Front.
https://en.wikipedia.org/wiki/Italian_general_election,_1948
(Even without the massive US aid, the Christian Democrats would still have powerful advantages, like the support of the Church. There was the famous scene in "Divorce Italian Style" where the priest, without of course mentioning any party by name, asks his parishioners to vote for a party that is both *Christian* and *democratic*:
)
In OTL if the Communists attempt an insurrection in the North--and there was some real fear they might do so after the attempted assassination of Togliatti--they will lose, period. Though it could be a very bloody business, as I note at
https://www.alternatehistory.com/forum/threads/togliatti-assassinated-july-14-1948.298756/