RUSSIA HAS revived a bitter historical dispute with Ukraine over ownership of the Crimean peninsula in an apparent attempt to guarantee the continued presence of its Black Sea fleet there.

Moscow has maintained a fleet there for more than two centuries - in the Tsarist, communist and post-Soviet eras. But, with less than a decade to run on its lease on the base, Russia is worried that its days in Sevastopol are numbered.

Now it has launched what looks like a campaign to reabsorb Sevastopol into its own borders, sparking a full-blown diplomatic dispute that appears to be a flashpoint in a new cold war between Moscow and the West.

Moscow's powerful mayor, Yuri Luzhkov, said earlier this month that Sevastopol, currently part of Ukraine, should become part of Russia. He said Russia would try to get the port city back through the international courts.

A furious Ukraine retaliated by banning him from crossing its borders and by starting work on a draft law that would shut Russia out of Sevastopol when its lease on the base expires in 2017. It said its national security and territorial integrity was threatened. Moscow saw red. Senior politicians lined up to support Luzhkov and Moscow started declaring Ukrainian politicians persona non grata.

For Russia, it is a question of reversing what it considers to be a grave historical injustice. Russian empress Catherine the Great purloined Sevastopol for Russia in the 18th century. But, in 1954, then Soviet leader Nikita Khrushchev transferred ownership of the Crimea from the Russian Soviet Socialist Republic to the Ukrainian Soviet Socialist Republic, apparently on a whim. Russian nationalists say he did so after a drinking binge.

But when the USSR disintegrated, Russia woke up to discover one of its most important naval bases and a region it considered its own was in a foreign country. With Ukraine's pro-Western leadership pushing to join Nato, Russia's bitterness has turned to open hostility.

Former president Vladimir Putin has spoken in fearful tones of Nato having a base in Crimea and many residents of the famous port city agree.

"Imagine a Nato base in Sevastopol," Putin said earlier this year after a meeting with Ukrainian president Viktor Yushchenko.

And earlier this month, Russia celebrated the 225th anniversary of the Black Sea fleet in Sevastopol using the occasion as a springboard for what looks like a "Return Sevastopol" campaign.

To Ukrainian annoyance, more than 30 Russian warships drilled in the harbour as Russia's defence minister looked on.

The Russians cancelled a planned landing on the peninsula of marines and combat vehicles after the Ukrainians objected. But they went ahead with a celebratory concert on one of the town's main squares, complete with, before he was banned, Moscow's mayor.

"We won't give up our Sevastopol," the crowd chanted as they listened to Luzhkov's speech.

Pro-Moscow activists have been busy collecting signatures for Russia's base to be kept in Sevastopol permanently.

For Ukraine, a country still struggling to defuse bitter differences between the Russian-speaking east of the country and the Ukrainian-speaking west of the country, losing Sevastopol or Crimea is unthinkable. It is, therefore, mounting its own campaign of "Ukrainisation".

Ukrainian nationalists have tried to storm Black Sea fleet facilities, Ukrainian flags have multiplied, and the authorities have tried to make life more and more difficult for the Russian military.

Ukraine's latest gambit is a $20 million film about the Crimean War that will seek to topple the idea that Russians played a key role in defending Sevastopol from the British, French and Turks during the nineteenth-century conflict. It will instead have Ukrainian soldiers and sailors centrestage.

Russia says it has started building what could be an alternative base at the Black Sea port of Novorossisk but it's unclear how serious it is about that idea. Analysts say surrendering Sevastopol would be sacrilege for Kremlin hardliners.