Ahtisaari, 71, has been at the heart of a number of relatively small but generally successful peace initiatives over the past 20 years.

In 1989-90, he played a major role in the negotiations that led to the independence of Namibia in southwestern Africa. He has been the United Nations special envoy on the Kosovo status negotiations. He and his Crisis Management Initiative organization also played a major role in successfully resolving the status of the energy-rich Indonesian region of Aceh on northern Sumatra island in 2005.

The Norwegian Nobel Committee said Friday Ahtisaari had been selected from the 197 nominations received this year "for his important efforts, on several continents and over more than three decades, to resolve international conflicts. These efforts have contributed to a more peaceful world and to 'fraternity between nations' in Alfred Nobel's spirit."

Norwegian Foreign Minister Jonas Gahr Stoere said while touring Afghanistan, "Through his work as a diplomat, Ahtisaari has shown what a single human being can achieve. The Prize is in recognition of this."

There is a widespread consensus that Ahtisaari's prize is richly deserved. However, some critics are arguing that the Nobel Committee played it safe in awarding it to him. They argue that jailed Chinese human rights activists Hu Jia and Gao Zhisheng would have been far better choices.

For all of Ahtisaari's dedication, his work has never been controversial or personally dangerous to him. Hu and Gao have shown exceptional physical and moral courage in their activities. And like the late Soviet dissident Andrei Sakharov, who also won the Peace Prize, they have been working on a vastly larger and more important stage than Ahtisaari or many of the other nominees.

The Chinese government made very clear before the award was announced that it would be furious if either Hu or Gao, or both of them, was awarded the prize. In the past, Nobel panels defied the mighty Soviet Union to award the peace prize to Sakharov and the Nobel Prize for Literature to Alexander Solzhenitsyn, who died earlier this year.

Hu and Gao had been widely tipped to be heading the list of candidates. But China's foreign ministry said earlier that it hoped the prize would go to "the right person" and that in the past it had not always served its purpose of promoting world peace and human progress. This appeared to be a veiled reference to the award to the Dalai Lama, the exiled spiritual leader of Tibet's Buddhists, in 1989.

Hu had monitored human rights violations in China and had worked hard to keep international news outlets comprehensively and accurately informed about them. He was found guilty in April 2008 of inciting subversion, and was sent to jail for three and a half years.

Gao is an author and self-educated lawyer who had represented a number of defendants, including members of the banned Falun Gong religious movement. The Chinese government, with vivid memories of religious movements in the past, like the Taiping, that went political and caused massive unrest and even enormous civil wars, has cracked down on the Falun Gong, with its martial arts practices and apocalyptic beliefs, and monitors it very closely.

Gao has had an even more difficult time at the hands of the Beijing authorities than Hu. He has experienced physical attacks and may have been the subject of an attempt to murder him. He was removed from his home in September 2007 and his current whereabouts are unknown. Some of his supporters have claimed that he has been exposed to torture and may even have been driven to a suicide attempt. Supporters of his nomination argued that it might prove crucial in saving his life.

The Nobel Peace Prize will be awarded to Ahtisaari on Dec. 10 in Oslo. He will receive a financial award worth $1.4 million, or 1.02 million euros.