"More than anything, the prize is intended as encouragement for the Tunisian people who have laid the groundwork for a national fraternity which the committee hopes will be followed by other countries," the committee said.
The National Dialogue Quartet comprises four key organizations in Tunisian civil society, including the Tunisian General Labor Union, the Tunisian Confederation of Industry, Trade and Handicrafts, the Tunisian Human Rights League and the Tunisian Order of Lawyers.
But the award also seemed to more broadly honor a nation where the Arab Spring began after street vendor Mohamed Bouazizi set himself on fire on Dec. 17, 2010, to protest his helplessness after his wares were confiscated by corrupt local authorities.
Tunisian President Beji Caid Essebsi called the award a sign of hope only a day after a high-profile assassination attempt against a secular politician.
"I know the situation is currently very difficult in Tunisia," he said in a video posted on Facebook. "And despite all the rumors circulating about yesterday's incident [the attempted assassination], we have received happy news. Not everything is dark and grim."
For the winners, too, the Nobel was a stunning acknowledgment of one of the Arab Spring's promising fronts, which is often overshadowed by the hijacked hopes in other countries such as Libya, Egypt and Syria.
Tunisia has been spared the widespread bloodshed that has plagued the rest of the Arab world since uprisings swept the region four years ago. But the political openness that followed the revolt also allowed extremists to organize and challenge the country's secular traditions.
"I am astonished, so happy. There are calls coming in from all over the world. I can barely believe this is happening," a breathless Ali Zeddini, vice president of the Tunisian Human Rights League, told The Washington Post.
He acknowledged, however, that the Nobel decision comes "at a time of great stress and tension in Tunisia."
"It has reminded us of our accomplishments, and places great responsibility on us to maintain peace and our democracy through dialogue," he said.
Critics, however, suggested that the Nobel committee had failed to fully acknowledge the extent of the political violence still gripping Tunisia.
As recently as Thursday, for instance, a secular legislator and soccer king, Ridha Charfeddine, escaped an assassination attempt after gunmen opened fire on him in the coastal city of Sousse.
"This decision hit me like a rock," said Hamdadi el-Aouni, a Berlin-based Tunisian political scientist , referring to the Nobel. "I do not know what these people of the committee where thinking. I've just come back from Tunisia. There is no state, just total chaos. And there is certainly no peace there."
But the Nobel was widely hailed as a nod toward the ability of Tunisia's political and civil groups to seek dialogue while other Arab Spring neighbors have stumbled back to bloody power struggles or tighter rule.
In a congratulatory Twitter post, Tunisia's Islamist Ennahda party hailed the award as "a victory for all Tunisians, who showed strength, patience & commitment to peace & democracy in face of countless challenges."
The group's general secretary, Houcine Abassi, told the Associated Press, the group was "overwhelmed" by the Nobel selection.
"It's a prize that crowns more than two years of efforts deployed by the quartet when the country was in danger on all fronts," he said.
Michael Ayari, a senior analyst with the International Crisis Group who lives in Tunis, said the Nobel decision "allows people to maintain hope."
"The international community still believes in Tunisian democracy," he said. "And we know that with dialogue we can solve our conflicts."
Today, Tunisia's political transition remains tenuous and far from complete. But the progress made thus far came about because of the ability of civil society organizations to reach a "landmark compromise" between the government and opposition groups, according to Mohamed Kerrou, a nonresident scholar at the Carnegie Middle East Center.
"Tunisia's consensus was only possible thanks to an inclusive national dialogue brokered by the Quartet," Kerrou wrote.
Following the fall of President Zine el-Abidine Ben Ali in 2011, Tunisia's democracy emerged as the strongest in the Arab world even as it confronts still-deep divisions and challenges.
After a dialogue between Islamist and secular lawmakers, Tunisia last year passed a constitution that was seen as one of the most liberal in the Arab world and that won praise from human rights groups. Last year, Tunisia also held its first democratic presidential elections, voting in Essebsi, an 88-year-old who formerly served under the repressive regime of Habib Bourguiba.
Yet the nation has since struggled to find a lasting peace, and fears have reemerged about the threat to democracy following a crackdown against rising Islamist extremism.
After a Tunisian gunman believed to have received training from Islamists in Libya killed 38 people at the beach resort of Sousse last June, the government vowed to shut down extremist mosques and take other steps to curb terror.
As often in the Nobel Peace Prize, the announcement amounted to a stunner. The Tunisian alliance had not been mentioned as a leading contender. As is traditional, the winner was kept secret until 11 a.m. local time in Oslo, when the name was divulged by Kaci Kullmann Five, chairwoman of the five-member prize committee appointed by the Norwegian Parliament.
The peace prize, first awarded in 1901, is seen by many as the most influential - and political - of the awards established by Swedish industrialist Alfred Nobel.
The decision marked the second consecutive peace prize to honor a recipient in the Muslim world. Last year, the award went to Pakistani education activist Malala Yousafzai. She shared the prize with Indian Kailash Satyarthi, a champion for childhood education.
