Mohmed Abdulkarim, 24, of Westminster, London, has been charged with assisting a foreign intelligence service believed to be Iran. Nouman Essghir, also 24 and from Westminster, has been charged with entering a prohibited place for a purpose prejudicial to the UK on 22 August.
Both men appeared at Westminster Magistrates' Court on Tuesday. They are charged under the 2023 National Security Act. Essghir has been remanded in custody. Abdulkarim has been granted bail with conditions including passport surrender.
The charges relate to an alleged plot at RAF Fairford in Gloucestershire. On 27 September, three suspicious vans bearing the logo "Fuel2You" were spotted near the US-operated airbase, prompting a major incident declaration. Dozens of residents were evacuated. Police found no explosive materials in the vans but seized petrol. Five men were arrested that day. One had called 999 to report what was happening.
Essghir was one of the five arrested in September on suspicion of committing offences under the Explosives Act and preparation of a terrorist act. All five were released on police bail the following day. Essghir was re-arrested on 20 October.
Assistant Commissioner Laurence Taylor said counter-terror police had seen "a range of incidents in recent months that we believe have been directed by the Iranian state". He said the decision to release the men initially "has led to swifter progress, better evidence, and ultimately us securing the charges that I've announced today."
Eight men have been arrested as part of the investigation. The case will be heard next at the Old Bailey on 20 November.
Iran has previously denied any involvement in the incident at RAF Fairford.