As Sri Lankan government ministers and senior Tamil Tiger rebels sit around a table in a Swiss chateau today, diplomats hope to build confidence between the two sides but say if they fail there may be war.
The island's minority Tamil-dominated north and east has been calm since the two sides agreed to meet, but if talks collapse many fear a return to violence last seen in December and January which killed over 200, all but destroying a fragile 2002 truce.
"If they fail, I really do believe there will be a war," said a European diplomat on condition of anonymity. "But I think it's very unlikely. What we'll probably see is some trust-building measures and a date and venue for more talks."
The Liberation Tigers of Tamil Eelam (LTTE), whose two-decade fight for a Tamil state has killed more than 64,000 people on both sides, warn that the meeting in the Chateau de Bossey outside Geneva will decide if there is peace or fighting.
But diplomats, officials and analysts say the Tigers will state their complaints, possibly set a deadline for action by the government and the two sides will agree to meet again, possibly in Norway or Iceland. New crossing points between army and rebel territory may also be announced.
They hope this will help reduce tension that peaked in late January after a string of suspected rebel attacks on the military which sent the stock market plunging and raised fears of new fighting in an area still dominated by bombed buildings and minefields from the last war.
The Tigers denied involvement in the attacks, but few believed them. The ambushes and attacks ceased after Norwegian envoy Erik Solheim brokered an agreement for the Switzerland meeting.