Turkey and Armenia last night finally signed a landmark accord to restore ties and open their shared border after a century of hostility stemming from the First World War mass-killing of Armenians by Ottoman forces.
But in an indication of the many pitfalls that lie ahead of its implementation, the ceremony was marred by a three-hour delay due to last-minute disagreements on the wording of statements, forcing the American secretary of state, Hillary Clinton, to engage in intense discussions to salvage a deal.
Ahmet Davutoglu, the Turkish foreign minister, and his Armenian counterpart, Edward Nalbandian, signed the accord in Zurich, ending speculation that days of angry protests might scupper the deal.
The accords mark a new chapter in relations after generations of bitterness over Armenian claims of genocide by Turkish Ottoman forces nearly a century ago. Under the agreement, the two countries will form a joint historical commission to examine the issue.
The Turkish and Armenian parliaments must now approve the deal in the face of opposition from nationalists on both sides and an Armenian diaspora which insists that Turkey acknowledge the killings of up to 1.5 million Armenians as genocide.
The agreement, the culmination of more than a year of intensive diplomacy, will commit both countries to reopen their land border and restore diplomatic ties, which Turkey severed in 1993 over Armenia's occupation of Nagorno-Karabakh, a territory claimed by Ankara's ally, Azerbaijan.
Politicians and analysts have hailed the accord as a major breakthrough. "It's the beginning of a new era not only for Turkish-Armenian relations but also for the entire Caucasus region, including Russia and Iran," said Cengiz Aktar, professor of EU studies at Bahcesehir university in Istanbul.
"It won't be easy to resolve the many sclerotic issues and there are no quick fixes. But it's an extremely important step."
Last week, Armenia's president, Serzh Sargsyan, faced angry demonstrations on a tour designed to sell the agreement to Armenian communities in the US, Russia, France and Lebanon. Around 10,000 nationalists, some holding banners reading "No to Turkish preconditions" and "No to concessions to Turkey" protested in the Armenian capital, Yerevan.
Turkey admits many Armenians died in the final days of the Ottoman empire but disputes the numbers, while claiming many were victims of disease. The Turkish official narrative also insists many Turks were victims of Armenian violence.
The agreement also commits Armenia to work with Azerbaijan towards a resolution of the Nagorno-Karabakh dispute.
Some 30,000 people died after war broke out in the enclave in the early 1990s following the collapse of the Soviet Union.