British nationals Mohmed Ahmad Abdulkarim and Nouman Essghir, both aged 24 and from London, were charged under the National Security Act, the Crown Prosecution Service said. They are due to appear in court later Tuesday.
Abdulkarim is charged with assisting Iran's intelligence service and Essghir with entering a prohibited place for a purpose prejudicial to the U.K.
RAF Fairford, in western England, has been used by American bombers to strike Iran during this year’s war.
Essghir was arrested outside the base on Sept. 27, when armed police officers and army bomb-disposal experts swarmed the rural area. Scores of residents were evacuated from their homes as police and army bomb-disposal experts searched for explosives.
Police later said they had found a quantity of an accelerant — gasoline — in vans at the scene, but no explosives.
Essghir was initially released on bail before being re-arrested last week. Abdulkarim was arrested in the past week. Six other men have been arrested and released on bail as investigations continue.
British authorities have linked Tehran to the incident, which led the U.S. to pull its bombers from RAF Fairford. Prime Minister Andy Burnham said that the apparent plot was "almost certainly" directed by Iran’s Revolutionary Guard.
