President Santos thanks the people who campaigned for the peace accord to be approved in the referendum, after winning the Nobel peace prize. Photograph: John Vizcaino/Reuters

The winner of this year’s Nobel peace prize was, for reasons of time difference, still asleep when the honour was announced on Friday morning – it was the middle of the night in Colombia, where Juan Manuel Santos is president. According to Norwegian television, his staff are so loyal they refused to awake him.

The award to Santos was remarkable, mostly for its timing, in a different way. It came just days after Colombians had voted to reject a peace deal that his government had secured after four years’ negotiation with the Farc guerrilla group.

The Nobel committee made it clear that the award was didactic: given to someone who had failed to secure peace so far, but in the hope that he might succeed. The committee said: “The referendum was not a vote for or against peace. What the No side rejected was not the desire for peace, but a specific peace agreement.”

The plebiscite last Sunday was supposed to bring an end to the world’s longest-running war, between the Colombian military and the Marxist guerrilla insurrection of Farc, the Fuerzas Armadas Revolucionarias de Colombia. Farc was founded in 1964 in response to an army attack on a rural enclave occupied by armed peasants affiliated to the Communist party. Farc’s protest originated in the systemic concentration of agriculture in the hands of a few landowners which had continued from Spanish colonial rule into independence.

The peace deal had been acclaimed by Pope Francis, President Obama and diplomats from around the world. Two weeks ago, it was signed in Cartagena in front of the world’s media and a host of global dignitaries, only for the Colombian people to reject the accord by a margin of 0.4% of the vote.

While Santos had received acclaim internationally, as the Nobel prize attests, he faced a much tougher battle at home. There, he had been confronted by the former president Álvaro Uribe, who orchestrated the No campaign. Uribe, whose father was killed by Farc during a kidnap attempt in 1983, was unrelenting in his criticism of a deal he said was too soft on the movement he characterised as “terrorists and narco-traffickers”.

Santos now sends his diplomats back to Havana to try to renegotiate peace. If he can manage that he will be a worthy successor to the likes of Yitzhak Rabin and Yasser Arafat, Nelson Mandela, Mikhail Gorbachev and Martin Luther King. The prize may yet help revive a stalled process that looked to be unravelling rapidly – and dangerously.

Juan Manuel Santos Calderón comes from one of the wealthy and weighty families that constitute a spine of continuity among Colombia’s educated urban elite, Colombia Permanente as people say. From the beginning of the 20th century, the Santos family owned a majority stake in the country’s most influential daily newspaper, El Tiempo, which it maintained until 2007.

Juan Manuel was born in 1951 in the capital and family seat, Bogotá, and, after a brief spell in the navy, studied business and finance at the University of Kansas. While a representative for Colombia’s coffee growers at the International Coffee Federation in London, he completed a master’s at the LSE, then another at Harvard, before returning to become deputy director of the family newspaper.

Alvaro Uribe leaves a meeting with President Santos after the peace deal, which he had campaigned against, was rejected. Photograph: Guillermo Legaria/AFP/Getty Images

In 2005, Santos founded and led the Social Party of National Unity, which sought to fix the old rupture between liberal and conservative parties that had taken Colombia to civil war from 1948 to 1958. The party promised to support Uribe’s presidency, then in the middle of Plan Colombia, the US-backed onslaught against Farc.

In 2006, Santos was appointed Uribe’s minister of defence. In May 2009, Santos resigned, only to fight and win the 2010 presidential election against Uribe’s nominee on a platform that pledged to negotiate peace.

It was not peace with Farc, however, which first catapulted Colombia’s new president on to the world stage: it was his dramatic proposal to rewrite and, if necessary, tear up the language and premise of the “war on drugs”.

Santos first revealed his intention in an interview with this newspaper in 2011, saying: “The world needs to discuss new approaches… we are basically still thinking within the same framework as we have done for the last 40 years… A new approach should try and take away the violent profit that comes with drug trafficking… If that means legalising, and the world thinks that’s the solution, I will welcome it.”

Over the next three years, Santos addressed the UN and gathered support from a coalition of South American presidents who agreed that the “producing countries” – and not the “consuming countries” of the west – were the ones suffering most from the violence and carnage that resulted from the war on drugs.

Santos’s intervention was, and remains, the most dramatic in challenging the west to take greater responsibility for the impact of the “war on drugs”. As he explained to the Observer, for his country, drugs are “a matter of national security”, whereas for other consuming countries, “it is mainly a health and crime issue”. The price of feeding the west’s appetite for drugs, along with the pressures of fighting Farc, threatened to render Colombia a “failed state” in the 90s. “We have gone through a tremendous experience – dramatic and costly for a society to live through. We have lost our best judges, our best politicians, our best journalists, our best policemen in this fight against drugs and the problem’s still there.”

Colombia’s ambassador to London, Néstor Osorio Londoño, explained to the Observer how Santos’s narco-traffic initiative was “inextricably linked to the peace process. The accord requires a major trafficking organisation, Farc, to join the Colombian army to eradicate coca-growing. This is historic, Santos’s way of saying to the world, ‘We’re doing our bit, now you do yours.’” The history of that peace process has come to define the Santos presidency, lose him the plebiscite, but now win the Nobel prize.

It began with Santos instructing his former closest aide at the defence ministry, Sergio Jaramillo, to conduct what Jaramillo described to the Observer as “secret talks about talks about talks”, with Farc as far back as 2011.

The crucial difference between this and many previously failed attempts at peace was that Santos agreed that senior Colombian military officials would attend the peace negotiations. Farc’s commanders have told the Observer how crucial this was: “One of the best signals that we received, that Santos was really heading for peace, is that he sent active military generals to talk peace. That was something we had always requested in previous peace talks – but never got,” said Farc’s supreme commander, Timoleón Londoño, known as Timochenko.

At the core of the peace deal was a pledge by Farc to surrender their weapons and take part in elective politics and for the government to enact major land reforms. Farc leaders could avoid harsh prison sentences by admitting their guilt and offering compensation to victims. It was a huge gamble and seemed until last weekend to have paid off. But at the heart of the campaign was a personal battle between Santos and his former mentor Uribe.

They could not be more different: Santos urban and urbane, Uribe from a cattle-ranching family, flamboyant, with a populist touch. From the start of the peace process, Uribe, mostly through Twitter, had launched a vicious campaign against Santos and the peace process. The great Colombian writer Héctor Abad wrote after the vote that between Santos and Uribe there exists “a personal affair, too personal, of pure vanity. Peace, yes, but signed by me”. Abad now tells the Observer, in rage at Uribe’s campaign: “Uribe said that ‘Santos was a Farc infiltrator in my government’. They put his photo on big hoardings all around the country surrounded by Timochenko, [Cuban leader Raul] Castro and [Venezuelan president Nicolás] Maduro. It was awful… The Nobel prize gives us new life, not only Santos. Now the people will understand the terrible campaign based on fear and lies.”

The No campaign manager, Juan Carlos Vélez, boasted last week, in an extraordinary interview in La República, that he deliberately set out to inflame public opinion and that the campaign had purposefully avoided telling the public about the real contents of the peace deal. “There were no winners last Sunday,” one senior official close to the talks said. “Santos lost because he thought a deal with Farc was all he needed and failed to reach other communities in Colombia, not least those who didn’t vote. Farc lost because they weren’t contrite early enough and Uribe lost because his was a campaign of hate and fear based on the past and not the future.”

Demonstrators march for peace through the streets of Medellin on the eve of the referendum. Photograph: Luis Eduardo Noriega A./EPA

But Uribe has won a chair at the next round of negotiations, from which he has been hitherto excluded. Quite where a compromise will come from is hard to see. Uribe said the agreement needs to be renegotiated while Timochenko has said Farc will not change “so much as a comma”.

However, Farc and the government negotiators did release a joint statement on Friday saying: “Proposals for changes and clarifications that result from the process [of talks between the Santos government and so-called Uribista promoters of No] will be discussed by the government and Farc to give everyone guarantees.”

A bilateral truce has been extended but only to the end of this month. The biggest prize of all – peace for Colombia – remains tantalisingly out of reach, for now. The Nobel peace laureate who has so far taken his country to the brink of peace, but no further, must now try to stop a slide back to war.

Born Juan Manuel Santos Calderón 10 August 1951 in Bogotá, Colombia, to a political family. Santos attended a private school in Bogotá before briefly enlisting in the Colombian navy and, later, studying in the US and England. Deputy director of El Tiempo newspaper before serving in government. Married with three children.

Best of times Awarded the Nobel peace prize last week for his efforts in negotiating a peace deal between the Colombian government and Farc.

Worst of times Colombians voting to reject the peace deal he delivered after four years of painstaking negotiations. The deal, if accepted, could have ended 52 years of war with Farc guerrillas.

What he says “Making peace is much more difficult than making war because you need to change sentiments of people, people who have suffered, to try to persuade them to forgive.” New York Times interview.

What others say Labelled a “Castro-Chavista” by critics who say the peace deal would have allowed Farc commanders to participate in politics and that the deal was too soft on those accused of atrocities.