This is a very difficult question to answer--obviously, there are no documentary sources that would cover this, because it didn't happen.

But we do know a few things that could help us answer this hypothetical.

First, were the leaders of the Mafia patriotic? This is hard to answer, since they were intensely private (for good reason, as they were under constant investigation) and anything that they might have said in public, particularly during court proceedings, is obviously self-serving. If we’re talking about the Mafia from the 1950s to the 1980s, most of the leaders were first- or second-generation Americans who, on some level, had to be grateful to the country that let them prosper. On the other hand, they were under constant attack from the federal government (at least after the Kefauver Committee, 1950-51) and were not disposed to look kindly on it.

Mario Puzo had absolutely no first-hand experience of the Mafia, yet he later wrote of having been approached by those “in the know” who were certain he must have been connected himself. That’s limited evidence that the book captures, on some levels, the attitudes of Mafia members. What does Puzo say?

(Luckily I’ve just finished writing an article about Puzo, cynicism, capitalism, and gambling, so this is pretty fresh for me.)

Puzo posits that Mafioso resent all authority outside of their own. He traces it (based on dubious history) to a thousand-year tradition of the peasantry organizing against outside authority in Sicily. Still, he concedes that the Mafia itself, at least in Sicily, became an illiberal and repressive force, basically another branch of government that existed mostly to collect its own taxes, not champion the rights of the oppressed.

In Puzo’s The Godfather (and here he was drawing at least somewhat on his own mother, who was neither Sicilian nor a crime lord, but who was not shy about expressing herself and who may have well represented the mindset of that generation), Vito Corleone has a complete contempt for American government and particularly the idea that anyone should sacrifice themselves for a greater good. His son Michael enlists in WWII against his father’s wishes and receives acclaim as a war hero. When an outsider shows the Don a Life magazine article extolling his deeds (none of his intimates were so foolish), he grunts disdainfully and says, “He performs these miracles for strangers.”

Further, when other young men enlist, the Don is perplexed. One of them says that America has been good to him. “I have been good to him,” is the Don’s response.

From this literary reference, we can infer that American Mafiosi were not patriotic, in the sense that they would make sacrifices for their country.

But what about the Mafia’s involvement in CIA plots to assassinate Fidel Castro? Former CIA agent Robert Maheu, who later became Howard Hughes’ right hand man and facilitated mobster Johnny Rosselli receiving a finder’s fee when Hughes bought two Las Vegas casinos, wrote in his autobiography about his role in this plot. Yes, the mob was eager to see Castro gone, but not for patriotic reasons—they were mostly eager to remove Castro so they could reacquire their financial interests in Cuba, not because he posed a threat to U.S. security.

In short, they were primarily businessmen. It’s not likely that they would have led a commando-style resistance against a Soviet occupation out of sheer patriotism, though it is possible that they might have worked to disrupt the occupation if the Soviets interfered with their money-making (which they certainly would have). Possibly if there was a breakdown in authority they would have exerted control over sections of urban areas out of self-preservation. Possibly they would have used their contacts in labor unions to sabotage infrastructure. But remember that the Mafia’s power rested on its political connections even more than its firepower. When police can be bribed not to investigate the firebombing of a trucking company, the Mafia can retain control. But the Soviet occupation may not have been so easy to co-opt.