A fresh episode emerged in the intensifying tensions between Tehran and Washington after a top Iranian intelligence official declared a moment of triumph from a "severe blow" to US intelligence.

At a rare press conference in Tehran July 22, an official described as the chief of the counterespionage department of Iran's Intelligence Ministry announced that 17 Iranian individuals had been arrested for collaborating with the CIA. A number of those "spies" have been convicted of "spreading corruption on earth," a charge punishable by execution under the Islamic Republic's penal code.

The unnamed intelligence official noted that the convicts operated as isolated cells, each working closely with separate CIA intelligence officers, who lured them into espionage on the sidelines of academic conferences across Europe, Africa and Asia, as well as during US visa application interviews in American missions with promises of visa facilitation and cash, among other incentives. The officer noted that those people were tasked with "infiltrating" key military and nuclear facilities under the guise of "advisers and contractors." He said that none held key decision-making positions.

"Infiltration" has been a recurring motif in speeches by Iran's Supreme Leader Ayatollah Ali Khamenei. The term has come to mean a Western plot to erode the Iranian establishment from within.