Israeli defense officials believe that by the end of this year Iran will start taking delivery of an advanced Russian anti-aircraft system to defend its nuclear facilities against American or Israeli air strikes.

Speaking to The Jerusalem Post, the unnamed officials said several units of the S-300 anti-aircraft system, recognized as one of the very best anti-aircraft systems in the world, will be delivered to Iran via Belarus.

Investigative journalist Edwin Black wrote on his website The Cutting Edge earlier this month that a massive Israeli air force exercise over Greece in June was aimed at developing a plan of attack that would neutralize the S-300. Greece has several S-300 units deployed in Crete, and reportedly allowed Israel to conduct numerous test runs against the system.