Iran is Israel’s arch foe and the Jewish state accuses Tehran of trying to develop a nuclear weapon. By contrast, Russia has the strongest ties with Iran of any major power and has repeatedly urged restraint in the nuclear standoff.

  Israel, like the U.S. and much of the international community, believes ayatollahs’ program is aimed at developing a nuclear bomb, which Iran denies. While Jerusalem says it hopes diplomacy will resolve the nuclear standoff, it has not ruled out military action and Iran has frequently mentioned it could suffer a military strike from Israel or its allies.

  Israel has been on the forefront of pushing for sanctions, and Mr. Netanyahu said Monday they could be effective since 80 percent of the Iranian economy was based on energy. Russia generally has resisted new sanctions but has shown increasing frustration over the past week as Tehran proceeds with uranium enrichment despite international pressure.

  Mr. Netanyahu highlighted that in his talks with Mr. Medvedev he noticed a shift in the Russian position. “I can say that Russia definitely understands there is a need to prevent Iran from obtaining nuclear weapons and it understands that steps must be taken,” he said. “I think that Russia understands Iran’s direction very well and is considering what to do with other members of the Security Council.”

  Last week, Iran announced its decision to enrich uranium to higher levels, sparking warnings from President Barack Obama of punishing sanctions against the Islamic regime.

  Russia has also yet to fulfil a contract to deliver sophisticated S-300 missile systems to Tehran, a deal that has worried Israel as it would significantly strengthen Iranian air defences against military action. 

The deputy secretary of the Russian security council Vladimir Nazarov said Sunday there was no reason not to send Iran the S-300 missile system, saying a “contract was signed which we must fulfil.”

 These declarations were also meant to send a message to Israel that it does not approve the resumption of its arms sales to Georgia, which were frozen in August 2008.  According to the Itar-Tass, Israel resumed the sale of arms to Georgia and “is no longer limiting itself to the sale of UAVs [drones],” which are perceived to be defensive weapons. The truck-mounted S-300 can shoot down hostile missiles or aircraft up to 150 km [90 miles] away. 

  In 1981, Israeli warplanes destroyed an Iraqi nuclear reactor, and what is believed to be an Israeli air attack in 2007 destroyed what the U.S. says was a nearly finished nuclear reactor in Syria that would have been able to produce plutonium.

See : Article in  The Jerusalem Post – ‘Russia: S-300 delivery delayed’