The following article written by Prof. the Hon. Gareth Evans was originally published in the European Voice.

We might say it’s pure reason, but for most of us intensely engaged in public policy issues there is always an emotional trigger. And that’s particularly true in the struggle to overcome the world’s terrible, age-old cynicism and indifference to mass atrocities.

For many the trigger is scarifying memories of the Holocaust, for others losing friends or relatives in Rwanda or Srebrenica. For public officials it’s often the shame of knowing they could have done more – much more – to stir leaders and publics into effective action.

My own emotional and intellectual journey began in Cambodia four decades ago. I was a young Australian making my first trip to Europe, and spent six months getting there – wending my way through a dozen countries in Asia, and a few more in Africa and the Middle East.

I spent many hours and days on student campuses and hangouts, and in hard-class cross-country trains and ramshackle buses, getting to know scores of the liveliest and brightest people of my generation.

In the years since then, I have often come across Indonesians, Singaporeans, Malaysians, Thais, Vietnamese, Indians, Pakistanis, and others whom I had met on the road on that trip, or who were there at the time and had a store of common experiences to exchange.

But there is just one country, Cambodia, from which I never again saw a single one of those young men and women. Nor anyone just like them.

The reason, I am sadly certain, is that every last one of them died a few years later under Pol Pot’s murderous genocidal regime – either targeted for execution in the killing fields as a middle-class intellectual or dying, as more than a million did, from starvation and disease in forced labour in the countryside.

That haunting memory was a core motivation in the gruelling years I spent in the late 1980s and early 1990s as Australian foreign minister, working along with my south-east Asian, Chinese, American, and UN colleagues, to find and implement a sustainable basis for peace in Cambodia.

It was a recurring motif as I watched, impotently and from a distance, the tragic events in Central Africa and the Balkans in the mid – to late 1990s.

And it was what drove me to work with colleagues round the world on finding, once and for all, a conceptual and practical answer that would unite the international community in preventing and responding to mass atrocity crimes.

“The responsibility to protect” – “R2P” in this age of acronymomania – was the result, unanimously embraced by the United Nations General Assembly, meeting at head-of-state and government level at the UN’s World Summit in 2005.

R2P language deliberately turned the old “right to intervene” language on its head, focusing not on any rights of great and powerful nations to throw their weight around, but on the responsibility of all states to meet the needs of the powerless.

In the first instance, the responsibility to protect a country’s people from mass atrocity crimes lies with its own government; but if it proves unable, or unwilling, a wider responsibility lies with other members of the international community to assist preventively and, if necessary, react effectively, with military intervention an option in extreme cases, but only as a last resort and if the UN Security Council agrees.

In this world of cynicism, double standards, crude assertions of national interest, high-level realpolitik, and low-level manoeuvring for political advantage, it is very easy to believe that ideas do not matter much. But some do, and there are few with the potential to matter more for good – not only in theory but in practice – than that of the responsibility to protect.