Philip Hensher: The voices of the Nobel Peace Prize winners have just got louder

In August 1976, British troops had been deployed in Northern Ireland for exactly seven years. There seemed no prospect of any resolution to what had become known as the Troubles.

On 10 August, a tragically pointless event took place. British forces shot at an IRA fugitive called Danny Lennon in his car, and killed him. The car drove off the road, and killed three children. Their mother, Anne Maguire, survived. The horrifying accident was witnessed by Betty Williams, driving in her car.

She went to help, but could do nothing.

Immediately, Betty Williams started a petition with the Maguire children's aunt, Mairead Corrigan; shortly afterwards they founded an organisation called Women for Peace, later becoming the Community for Peace People. Marches of tens of thousands of people took place, denounced by the IRA.

Who was the petition addressed to? What were the demands of the organisation? Well, to some active participants, their involvement seemed naive. But it came from a belief without which nothing would ever get better; this situation can't go on. We must do something. We must have peace.

And in 1977, Corrigan and Williams were awarded the Nobel Peace Prize. It was an extraordinary thing for the Nobel committee to do. The women were not politicians; they hardly had a programme. They had merely stood up in an entrenched situation and said, "Neither this way, nor the other way, but things must change." Only a year after that brave gesture, the Nobel committee members came to the conclusion that that was good enough for them, and that they should bring it to the world's attention.

This year, the Nobel prize went to two Liberian women and a Yemeni woman activist: the elected Liberian president, Ellen Johnson Sirleaf, Liberian activist Leymah Gbowee, and the Yemeni Tawakul Karman, who at 32 is the youngest winner of the prize since Mairead Corrigan. The theme of this year's prize is the non-violent contribution of women to democracy and politics. It's well within the best traditions of the prize.

Repeatedly, the Nobel Peace Prize has sought to find a third way between entrenched positions by focusing on the role of women in the political process.

The Nobel prize for peace is often remembered for its occasionally bizarre decisions which subsequent events have not justified. Tom Lehrer said that he gave up the practice of satire on hearing that Henry Kissinger had been awarded the Nobel Peace Prize. The bien-pensant opinion of the moment led the committee, on occasion, to reward President Obama while he was still deciding whether he wanted to keep or change the carpet in the Oval Office; one wonders, too, whether the justification for rewarding Al Gore for climate change activism will really stand up, or whether, in time, it will look as tattered as 1994's award to Arafat, Peres and Rabin.

Still, the Norwegian committee has shown an admirable tendency to avoid the safe option, and to award prizes while the issues involved are still very much alive. It showed itself at its absolute best last year in giving the prize to Liu Xiaobo. It gave Chinese dissidence a face and a cause; it confronted a government that the West is too apt to cower before; and, best of all, it made the Chinese government look incredibly stupid in creating a rival "Confucius Peace Prize" for politicians that the Chinese government approved of.

The committee has shown a robust taste for interfering in national politics when it considers that its values of liberal democracy and freedom could be propagated. Think of the award to Carl von Ossietzky in 1935 for his resistance within Nazi Germany; Andrei Sakharov in 1975; or Lech Walesa in 1983, no more than three years after the founding of Solidarity.

Most consistently, however, it has been inclined to award it to women when they can act, as Corrigan and Williams did, as an alternative to a situation of impasse. Aung San Suu Kyi is a genuine alternative to the Burmese generals and offers a future for her country; after the prize, many more people knew of her. The same is true of Shirin Ebadi and Rigoberta Menchu and perhaps, of Mother Teresa too.

The significance of the award of the prize to the Yemeni Tawakul Karman is that she stands outside the familiar scenario Western governments work with. In this region, the West has a bad tendency to support dubious governments on the basis that they are, at least, bulwarks against al-Qa'ida and other unruly groups – the Roosevelt doctrine, based on the apocryphal statement that the Nicaraguan dictator Somoza (or, in other telling, the Dominican Trujillo) "may be a son of a bitch, but he's our son of a bitch".

The Yemeni situation is not currently under consideration by the UN Security Council. It can be thought of as one of those zero-sum analyses governments so enjoy: if not our dictator, then it can only slide into the hands of our enemies. The award of a prize to Karman, who stands for freedom of speech and opposition to President Saleh's government, presents a difficulty to the Yemeni government and its Western supporters. Suddenly, the situation no longer looks like a zero-sum game; there is another player, and its name, for the moment, is Karman's Women Journalists without Chains.

Some commentators would suggest that Ellen Johnson Sirleaf's administration doesn't deserve this honour; despite statements of the most honourable intentions, Liberian public life remains mired in corruption. In April this year, she rather remarkably told journalists that she was planning to charge an opposition politician with sedition for organising an anti-corruption rally, quickly saying that she had meant it as an April Fool's joke.

More interesting, perhaps, is the remarkable fact that the Norwegian committee is so confident in its values that it is prepared to give the prize to a person currently in the middle of a general election campaign in their own country – at least they waited until Barack Obama was elected before giving him the seal of approval. Johnson Sirleaf's value, it suggests, is that she is exactly the sort of politician who stands outside the usual choices of warlords.

And these bold interventions are very much the style of the Nobel. They have no hesitation in singling out a person at the very beginning of a long road of public dedication, and of infuriating oppressive and powerful governments. In their backing of the powerless, they have often made their best and most resonant awards to women, who can represent an overlooked third way in the blocked paths of national arguments. For these reasons, the committee should perhaps have preferred the Saudi activist Wajeha al-Huwaider, who this year has started small with a conspicuous campaign to allow women in Saudi Arabia to drive. That might have been a subtler intervention than openly backing a national presidential candidate during the election period.

To give a brave, suffering voice a platform from which to speak is what the Peace Prize does best, and we will listen to Karman the next time she speaks. Some time in the next 10 years, the prize will, I believe, go to a gay person in a difficult situation, just as the prize has gone to women who have spoken out. What it celebrates and enables is simply this: someone saying, "This can't go on. Someone ought to do something, and that someone might as well be me."