The United States attorney for the Southern District of New York, David Kelley, said in announcing the arrests on 15 March that the suspects have been under close surveillance for more than one year.
"As part of the overall scheme," Kelly said, "five of the defendants were charged with plotting to import into the United States various military weapons, including rocket-propelled grenade launchers, which are known as RPGs, shoulder-fired surface-to-air missiles, known as SAMs, and those were from Armenia, the Republic of Georgia, and other Eastern European countries."
While the weapons involved could have inflicted major casualties, Kelley said there is no sign the smugglers possessed weapons of mass destruction.
"Throughout this investigation," Kelley said, "through our eavesdropping of some 15,000 conversations by the defendants, or through countless surveillances 24-7 [around the clock] by the agents and investigators, we did not see any indication that the defendants had any capacity to obtain uranium or other chemical or biological weapon material. It didn't happen."
Two of the alleged ringleaders were identified as Artur Solomonyan, an Armenian citizen living in New York and Los Angeles, and Christiaan Dewet Spies, a South African citizen also living in New York.
Another defendant, Vato Machitidze, was shown on television as he was led handcuffed after his arrest in Manhattan.
A criminal complaint charged five of the participants with conspiring to transport destructive devices and 13 others with weapons trafficking. One of the 13 is still at large.
The FBI says the suspects proposed selling weapons to one of its informants who was posing as an arms buyer with ties to Al-Qaeda. They supplied him with digital pictures from a warehouse allegedly in Armenia, showing caches of Russian-made weapons.
The complaint charges that the defendants knew that the weapons may have been used for terrorist activities in the United States, particularly for bringing down commercial aircraft.
Andy Arena is a special FBI agent. "The criminal complaint charging the defendants reads like a Hollywood script, with one important distinction," Arena said. "Unlike the escapist fiction of a Hollywood thriller, the plot unveiled today was undeniably real."
The U.S. authorities said the sting operation was conducted with the assistance of law-enforcement authorities in Georgia and Armenia.
John Loftus, a former U.S. Justice Department prosecutor who closely follows terrorism issues, tells RFE/RL that Russian authorities also appeared to be very helpful in the investigation.
One of the weapons offered for sale, the Hornet antitank missile, is capable of penetrating the U.S.-made Abrams tank, according to arms experts. Among the other weapons offered for sale was the Igla missile, a shoulder-fired heat-seeking missile that can shoot down a commercial airplane.
The FBI says the defendants actually sold one of their informants eight machine guns and assault weapons, delivering them to warehouses in New York, Los Angeles, and Miami. The agency alleges the defendants offered to provide many more sophisticated weapons. The FBI says there were also discussions at some point concerning the delivery of uranium to be used for attacks in U.S. subways.
If convicted on all charges, the two alleged ringleaders each face up to 30 years in prison.
Authorities say the FBI is working with Armenian and Russian authorities to secure the weapons that were bound for the United States.