The US State Department finally acknowledged this week what has been common knowledge in the Middle East for months — that the Syrian civil war has become a conflict between regional and global players in which foreign fighters and proxies are playing a growing role.

An unnamed American official confirmed claims that have been made regularly over the past two years, that the Al-Qods force of the Iranian Revolutionary Guard Corps is fighting alongside Syrian troops to prop up the regime of President Bashar al-Assad.

Russia has already announced that it is standing by its Syrian ally and will continue sending him advanced weapons.

The Russian government has insisted that the S-300 anti-aircraft missiles and the P-800 Yakhont anti-shipping cruise missiles are for “defensive purposes”, and that Moscow is merely completing contracts signed years ago.

Russia’s commitment to the al-Assad cause was emphasised this week when 11 of its warships performed manoeuvres off the Syrian coast. It was the largest exercise in the Mediterranean undertaken by the Russian navy since the dissolution of the Soviet Union.

If Russia supplies Syria with the S-300 missiles, capable of hitting multiple targets at ranges of up to 200 kilometres, retaliatory air-strikes against regime targets will become more difficult.

However former Israeli military intelligence chief, retired general Amos Yadlin, commented that Israel could defend itself against the S-300.

Many experts believe that in its current state, the Syrian army is not capable of operating such a complex system.

But the threat was deemed serious enough by Israel for Prime Minister Benjamin Netanyahu to urge Russian President Vladimir Putin at a brief meeting at the Black Sea resort of Sochi two weeks ago, not to transfer the missiles to Syria.

The Russians have so far refused the Israeli and western appeals.