Adversaries they may be. But they enjoy a bantering rapport, cracking jokes, exchanging good-natured insults, and talking about the past.
But when the rival leaders of the estranged Greek- and Turkish-Cypriot communities meet today, it will be all business. They begin the most vital attempt in years to solve the long-running Cyprus problem before the island enters the European Union. The EU is set to approve Cyprus's membership in December, giving the Cyprus problem an effective deadline for the first time.
A big responsibility lies on the elderly shoulders of President Glafcos Clerides, the Greek Cypriot president of the internationally recognized government of Cyprus, and Rauf Denktas, the veteran Turkish Cypriot leader.
A comprehensive settlement would do more than guarantee peace, prosperity, and security for their communities. Success would also ensure a smooth expansion of the EU, remove a major source of friction between NATO allies, Greece and Turkey, and assist Ankara's troubled path to joining Europe. Hence the unprecedented interest and diplomatic input from both sides of the Atlantic.
Boosted by this new impetus, mediators hope the personal chemistry between the presidents will help break the stalemate. They will meet under UN auspices two or three times a week in the "buffer zone" that separates the two communities and hope to outline a comprehensive settlement by June.
Time presses both men, British-trained lawyers who have sparred over the negotiating table for more than three decades.
"If they can do a deal, they can both retire gracefully and get the plaudits," says a senior Western diplomat in Nicosia. "There's no doubt there's a perfectly acceptable solution out there, but the talks will be very arduous."
Mistrust goes back decades. Inter-communal violence erupted in 1963, three years after Cyprus won independence from Britain. Then, in 1974, Cyprus was sundered along religious and ethnic lines when Turkey invaded the northern part after a short-lived coup by the military junta then ruling Greece. Some 35,000 Turkish soldiers have remained stationed there ever since.
Numerous attempts to put Cyprus back together again have failed. Providing new momentum this time is Cyprus's looming accession to the EU and Turkey's desire to follow suit.
"In the EU, all Cypriots, both Greek and Turkish Cypriots, should feel secure with a guaranteed future in front of them," says George Vassiliou, Cyprus's chief EU negotiator.
The government of Cyprus, represented internationally by the Greek Cypriots, has been negotiating for the whole island to join even though a third of it is effectively beyond its control.
Denktas has spurned Greek-Cypriot offers to join the EU negotiations and insisted Cyprus must not enter the bloc before a settlement. At the same time, until just last month, he had been boycotting talks to reunify Cyprus, demanding formal acknowledgement of the Turkish-Cypriot state first.
Turkey recently raised the stakes by threatening it could annex the northern part of the island if Cyprus joins the EU without resolving the division. Greece, already an EU member, has warned it could block EU expansion altogether if Cyprus is not included.
While the EU does not relish the prospect of ushering in a country split by a Berlin-style wall, it has made clear Turkey will not have any veto. Last fall, Romano Prodi, the president of the EU commission, said Cyprus would enter "with or without a solution."
This has placed mounting pressure on Turkey. The entry of a divided Cyprus into the EU would leave a new member with 37 percent of its territory under occupation by an aspiring one.
"That could spell disaster for Turkey's foreign policy and for her own EU aspirations," says a senior European diplomat in Nicosia.
It was reportedly Turkey's cajoling that persuaded Denktas to return to the negotiating table. Turkey's business community had voiced concern about Denktas's stand and even in his own part of Cyprus there was been growing criticism of his "intransigence."
Years of international isolation and embargoes have left ordinary Turkish Cypriots impoverished. Per capita income is about $4,000 compared with $14,000 in the prosperous Greek-Cypriot south.
There has also been an alarming brain drain of young Turkish Cypriots, while settlers from mainland Turkey take their place. "I'd like to see my future in my country, but I can find no job, so I must leave," one Turkish Cypriot said during a recent debate televised in Turkey.
Polls show that the vast majority of Turkish Cypriots would like to enter the EU as soon as possible provided their security is guaranteed in a re-united Cyprus.
Crossing the "green line" in Nicosia, the world's last divided capital, is like entering a time warp. Glass high rises dominate the skyline in the bustling, cosmopolitan Greek-Cypriot half of the capital. Less than a mile away, in the Turkish-Cypriot half, the buildings are tattier and the shops shabby.
The outline of a UN-sponsored settlement would reunite the two sides under a loose federal system. Each community would enjoy a large degree of autonomy with a central government representing Cyprus internationally.
The Turkish Cypriots, who comprised 18 percent of the population in 1974 but were left in control of 37 percent of the island, would have to return "an appreciable amount of land" to enable a majority of the 167,000 displaced Greek Cypriots to return.
The issue of sovereignty, will be the trickiest, diplomats and officials say. While the Greek Cypriots seek a federal system of two regions operating under a single sovereignty, as called for in UN resolutions, Denktas wants a confederation of two independent sovereign states.