PBS has a brief but robust description of the history of The Syndicate in America. The story is mainly in regard to the establishment of Las Vegas casinos but it also touches on its role in influencing and working with law enforcement and intelligence agencies:

The Office of Strategic Services (later, the CIA) in fact employed the Syndicate in some covert operations. During World War II, the Syndicate helped with the invasion of Sicily and in protecting the Eastern waterfront against German sabotage. Some of the Syndicate’s major drug traffickers were used as informants and assassins in the Cold War. As one White House official described the government’s relationship with Lansky, “The government turned to him because hiring thugs was what government and business had been doing for a long time to control workers, and because it could conceive little other choice in the system at hand.”