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As mutual fear, mistrust and polarisation increases between Iran and Israel, an arms race between the two sworn enemies is gathering momentum.

Central to this is the Russian-made S-300 missile system.

It is one of the most advanced multi-target anti-aircraft missile systems in the world today and air power experts say it represents a formidable defence against conventional aircraft.

In 2005, Iran sought to buy five batteries of the S-300 from Russia in a deal believed to be worth around $800 million.

The S-300 would significantly boost Iran's defence capability at a time when it is concerned about the US military's presence in neighbouring Iraq and Afghanistan and Israeli threats to target its nuclear facilities.

But the S-300 deal has yet to go through and Israel has been engaging in some diplomatic wrangling in an attempt to ensure that it does not.

In early June 2009, Avigdor Lieberman, Israel's Russian-speaking foreign minister, visited Moscow.

He was on a mission to convince Russia to put an end to its arms deals with Iran and Syria and, in particular, to halt the sale and delivery of Russia's S-300 missile system to Iran.

Lieberman had a bargaining chip: If Russia went ahead with the sale to Iran, Israel might continue to provide hi-tec weapons to neighbouring Georgia, which engaged Russia in a war last year.

Filmmaker Abdallah el-Binni investigates this high-stakes game of brinkmanship as it threatens to spread to other countries in the region.

Countdown can be seen from Friday, October 02, 2009 at the following times GMT: Friday 1400, Saturday 0300, 1900 and Sunday 0600.