The head of Iran’s foreign military operations has described the Islamic State of Iraq and the Levant, known as Isis, as a “plague” which threatens Iran’s security and accused the US of doing little to stop their advance in neighbouring Iraq. The comments by Major General Qassem Soleimani underline fears in the Islamic Republic about potential spillover into its territory and follow reports that Tehran sent troops to neighbouring Iraq to prevent further advances by Isis, which took control of the Iraqi provincial capital Ramadi and Syria’s ancient city of Palmyra last week.