The arrests seemed orchestrated to deliver the Justice Department’s message directly to others in the business. All but one of the defendants were arrested on Tuesday in Las Vegas, where they were attending the Shooting, Hunting, Outdoor Trade Show and Conference, known as the SHOT Show, which is billed as “the world’s premier exposition of combined firearms, ammunition, archery, cutlery, outdoor apparel, optics, camping and related products and services.”

The drama began to unfold last spring in the sleek beachfront glamour of the Mandarin Oriental Hotel in Miami. There, on May 13, the curtain went up on a two-city sting worthy of a George Clooney caper.

After a closely guarded investigation that had taken more than two years, the cast was in place.

There was a mystery figure identified in the indictments as “Individual 1,” a former executive in the law enforcement and military equipment industry who clearly lent credibility to the business deal offered to the defendants, all described as business associates of his.

There was “Undercover Agent 1,” an F.B.I. agent posing as a representative of the defense minister of an unidentified African nation, Country A. And there was “Undercover Agent 2,” another agent posing as a procurement officer who reported directly to the defense minister.

Image Lanny Breuer, assistant attorney general, said “international cooperation is growing everyday.” Credit... Brendan Hoffman/Bloomberg News

Over two days in Miami, a number of executives sat down in separate meetings with the undercover team to discuss a sales opportunity. A week later, the undercover team moved to the Ritz-Carlton Hotel in Washington, where more executives sat down to talk.

The script varied only in the products on the shopping list.

In each case, the former sales executive said that a friend of his, a self-employed sales agent, was “tasked by Country A’s minister of defense with obtaining various defense articles for outfitting Country A’s presidential guard.”