Russian President Vladimir Putin today signed a decree formally ending a multi-year ban on selling Iran certain advanced defensive missile systems, notably the S-300 long-range anti-aircraft system.

Iran and Russia had a deal on the delivery of S-300 systems which was cancelled in 2010, amid intense Western (particularly Israeli) pressure. Though Russia maintained that the S-300, as a defense system, was not effected by UN arms embargoes, they still canceled the sale at the time.

Iran has since then focused on trying to make its own variants on defense systems, though this has focused on copying medium-range systems styled after Russia's PK37 Buk system.