Why Russia sells Syria arms
At an arms fair outside Moscow, five Russian tanks weave gracefully back and forth, their gun barrels rising and falling in time to a waltz. This unusual "tank ballet" was staged by a choreographer from the Bolshoi Ballet.
But these weapons were not built for dancing.
The tanks fire shells, machine guns spray bullets and the demonstration ground almost disappears in clouds of smoke.
Watching in the stands are potential clients: Delegations from Africa, Asia, the Middle East and the Gulf. Russia is the world's second largest arms exporter.
One of its customers is particularly controversial. This year, Syria is due to take delivery of Russian Buk-M2E surface to air missile systems, Pansir-S1 armoured rocket complexes and, according to some reports, Mig-29 fighter jets.
The deals were done before the outbreak of violence in Syria, but despite the fighting there Russia has no intention of tearing up the contracts.
"If the contract was signed before, it's necessary to fulfil," argues Igor Sevastyanov, deputy CEO of Rosoboronexport, the state-controlled arms exporter. "We fulfil our international obligations in accordance with international rules."
Russia employs the same argument for the helicopter gunships it is trying to send back to Syria.
These are Soviet-era attack helicopters which the Russians have been refurbishing. Last week, the Russian cargo ship which was transporting them had its insurance withdrawn in British waters and the vessel was forced to turn back, but Moscow says it is determined to complete the delivery.
The West accuses Russia of shoring up President Assad with weapons shipments. Russia accused the West of double standards.
"Why is the US determined to sell weapons to Bahrain after the Bahraini authorities, with help from the Saudis, suppressed the Arab Spring in Bahrain?" asks defence analyst Ruslan Pukhov, head of the arms trade think tank CAST.
"Russia doesn't see any problems selling weapons to Syria if the CIA and French and British secret services are shipping military hardware via Turkey to the rebels."
Russia's weapons contracts with Syria are worth billions of dollars. But Moscow denies that money is the main reason it continues to deliver military hardware to the Syrian authorities.
Russian officials fear that if the rebels push President Assad from power, radical Islamists could take his place and pose a threat to Russia's national security.
"This is not about kalashnikovs or helicopters. This is about very dangerous things near our door, " argues Andrei Klimov, deputy head of the Russian parliament's Foreign Affairs Committee. "This area is very close to my country and we'd like to avoid any kind of aggression from abroad. Otherwise it may become a hot point on the map near our borders."
Geo-politics are at play, too. Russia is concerned that if President Assad goes, its influence in the Middle East will disappear with him.
"Syria is the only country in the Middle East which follows our advice, this is the country where we can exercise certain tangible influence," says Ruslan Pukhov.
"Of course, the loss of Syria will mean we will have no influence in this region at all. It has some symbolic value for the Russian authorities and the foreign policy establishment as a sign of Russia as a great power."
Back at the arms show, the Presidential Guard march across the field in their tsarist-era uniforms.
Putin's Russia still sees itself as a superpower; as a country which has just as much right as America to sell weapons to whoever it wants, and gain influence wherever it can.
But the Kremlin is pragmatic. If Moscow begins to feel that it has more to lose than to gain from backing President Assad, the Syrian leader might find himself coming under pressure from the East as well as the West.
"We in Russia have no illusion about this regime," says Russian MP Andrei Klimov, "The only thing we'd like to have is a peaceful exit. We don't want to prolong this regime for decades or centuries. Our task is to find a peaceful solution as soon as possible."