THE Syrian port of Tartus is Russia's only military base outside the old Soviet Union. Moreover, Russia is the Syrian regime's only big-power friend. So the arrival there of the Admiral Kuznetsov aircraft-carrier and a few other warships earlier this month brought a warm welcome from Bashar Assad's defence minister, General Dawood Rajiha, who praised Russia's “honourable” support for his government.

Russia still blocks sanctions against Syria in the UN Security Council. But its navy offers little practical support. The laboriously assembled flotilla (shadowed by NATO vessels) did nothing to stop Cyprus impounding a cargo ship carrying tens of tonnes of Russian ammunition and explosives to Syria; it was released on condition it went to Turkey.

Russian officials say the visit is nothing to do with Syria's politics. Its warships visit often. It started modernising the near-derelict base, a legacy from Soviet times, in 2009. In any case they would be little use in a real fight: America's Sixth Fleet alone has probably more firepower than Russia's entire navy, which has barely 20 seaworthy surface ships.

The toppling of dictators in Iraq and Libya hurt Russia's oil interests and arms sales. It wants to avoid that in Syria. Its dilemma is that too much support for Mr Assad risks a future regime booting it out of Tartus, which is valued by Russian spooks and electronic snoopers. But too little may mean defeat for an old ally.