LONDON >> Just weeks after President Barack Obama won the Nobel Peace Prize in 2009, he ordered 30,000 additional U.S. troops to Afghanistan.

In 2012, the honor went to the European Union for creating a “fraternity between nations,” which has since slipped into nationalism and division over the migrant crisis and Britain’s vote to leave the bloc altogether.

Then on Friday, President Juan Manuel Santos of Colombia won the peace prize for his efforts to bring the country’s “civil war to an end” — only days after his country rejected the peace deal in a referendum.

How credible is the world’s most prestigious peace prize when peace itself is so scarce?

With successful peace deals few and far between, the Nobel Peace Prize has increasingly been awarded as an “encouragement,” said Thorbjorn Jagland, a member of the Nobel committee and its chairman from 2009 to 2015.

In other words, it is often a sort of nudge to persevere.

“Our mandate is to reward those who have done the most for peace over the past year,” Jagland said.

But when there is a dearth of actual peace, he added, “we have to award those who are trying.”

Some applaud the notion, pointing out that, as the world has amply demonstrated, it’s harder to make peace than war.

But others worry that, over time, the approach could devalue the prize.

“The peace prize has always been symbolic,” said Dominique Moisi, a senior adviser to the Institut Montaigne, a nonpartisan think tank in Paris. “But the symbol is shrinking.”

In many ways, the messages from the Nobel committee reflect an increasingly uncertain and complex world in which events, political alliances and global circumstances are constantly changing.

Whether the prize is aspirational or for something the winner has actually achieved is beside the point, argued Nancy Lindborg, president of the U.S. Institute of Peace, a government-funded organization. She called the Nobel Committee’s decision to award the peace prize to Santos — despite his failure to get a peace deal approved — consistent and commendable.

“It’s the Peace Prize Committee saying, ‘This is what we want to applaud,’” she said. “And you need leaders, whether individuals or entities, that stand for peaceful approaches, as opposed to resorting to belligerence.”

Critics of Obama note that he did, in fact, resort to belligerence.

He announced the 30,000-soldier surge into Afghanistan in a December 2009 speech at the U.S. Military Academy at West Point, less than two months after he had won the Nobel. He has conducted drone strikes that have killed civilians in places like Pakistan and Yemen, telling aides, “Let’s kill the people who are trying to kill us.” He has failed to keep a promise to close the U.S. prison in Guantanamo Bay, Cuba.

Many, including Obama himself, expressed surprise when he won the peace prize so early.

But Jagland, who led the committee at the time, said he had no regrets, calling it one of the “proudest decisions.” The nuclear deal with Iran that Obama and others eventually negotiated, he said, justified it.

“The prize was an award for something he started,” Jagland said. “Obama said early on that he would negotiate. It was an important move to avoid war in another region. Many others said bomb Iran.”

Still, Jagland acknowledged that the prize for the European Union was mistimed.

“The EU got the prize too late,” he said, although when it finally received the honor, “it was an opportunity to remind people of the EU’s achievements” at a time that cracks were appearing.

Critics are less forgiving.

“The prize to the EU came at the worst of times,” Moisi said. “The moment they got the prize, everything started to disintegrate.”

Of course, accusations of hypocrisy, skulduggery and political favoritism have been part of the Nobel Peace Prize for much of its history. There have been 19 years — including most of both World Wars — when the committee did not award one.

Mahatma Gandhi, the leader of India’s independence movement and a prominent pacifist, never won the prize despite being nominated five times from 1937 to 1948.

Geir Lundestad, a former secretary of the Nobel committee, has called Gandhi’s absence from the list of winners the “greatest” omission in the committee’s history.

“Gandhi could do without the Nobel Peace Prize,” he said. “Whether the Nobel committee can do without Gandhi is the question.”

One of the most contentious Nobel Prize awards came in 1945, when Cordell Hull, secretary of state during much of President Franklin D. Roosevelt’s administration, won for his work in founding the United Nations.

Critics were outraged because six years earlier, Hull had successfully pressed Roosevelt to deny asylum to 950 Jewish refugees fleeing Nazi persecution. They were aboard the ship St. Louis seeking entry to the United States, but the ship was forced to return to Europe, and more than a quarter of the passengers died in the Holocaust.

In another Nobel uproar that resonates to this day, Henry A. Kissinger was awarded the prize in 1973 for his negotiations as President Richard M. Nixon’s secretary of state on an armistice that halted the Vietnam War. Anti-war activists around the world protested in disbelief because of the Nixon administration’s intensive bombing campaigns in Vietnam, Laos and Cambodia.

The U.S. satirical songwriter Tom Lehrer famously said that when Kissinger won the prize, “Political satire became obsolete.”

Adding to the acrimony, Kissinger’s Vietnamese counterpart and co-winner, Foreign Minister Le Duc Tho, refused to accept the prize. Two Nobel Committee members resigned in protest.

The 1935 award given to Carl von Ossietzky, a German journalist and pacifist imprisoned for exposing Germany’s clandestine rearmament, was widely viewed as a condemnation of Nazism. The award so outraged Hitler that he banned German newspapers from mentioning it and forbade Germans from accepting the prize thereafter.

Four years later, Hitler was nominated for the prize by a Swedish parliamentarian, Erik Brandt, who apparently had meant it to be a satirical joke. The nomination incited outrage in Sweden, and Brandt withdrew it. According to the Norwegian Nobel Committee’s own website, Mussolini and Stalin were also nominated for the peace prize.

In the run-up to this year’s award, there had been some hope the Nobel Committee would award the prize to the White Helmets, a civilian group that has helped rescue civilians caught in the relentless aerial assaults on the Syrian city of Aleppo by government forces and their Russian allies.

But the desperation in Syria makes the Colombian president no less worthy of the prize, said Kenneth Roth, executive director of Human Rights Watch.

“The deliberate Russian and Syrian bombardment of civilians in Aleppo and elsewhere has been despicable — flouting the most basic rules of war — and it could use any spotlight available,” Roth said. “But encouraging a justice-compatible final peace deal in Colombia is also important.”

© 2016 The New York Times Company