There are two kinds of JIC meeting: those at which Australia, Canada, New Zealand and the US are represented; and those attended only by Britons. Britain's European allies do not attend any JIC meeting. The CIA Chief of Station in London normally attends all meetings, leaving when 'domestic' issues are discussed.

The JIC recently played a controversial role in compiling a dossier in which the UK government set out the threat posed by Iraq's Weapons of Mass Destruction in the run up to war. There were allegations that the dossier was "sexed up" prior to publication in order to bolster the case for military action. Evidence that the wording of the dossier was "strengthened" was presented to the Hutton Inquiry, a judicial review set up to investigate the circumstances leading up to the death of an eminent government weapons expert David Kelly who had criticised the wording of the dossier in off-the-record briefings to journalists. Dr. Kelly committed suicide shortly after his identity was confirmed to the media by the government. JIC members John Scarlett and Sir Richard Dearlove (head of MI6, the Secret Intelligence Service) gave evidence to the Inquiry in which they argued that the words used in the dossier were consistent with their assessment of the intelligence available at the time.