The Kigali Genocide Memorial is, on the surface, a peaceful place: a sunny terrace, lush greenery, and from the hill a sweeping view over the valley. Below the hill, however, lies sheer horror. 250,000 bodies are buried there – women, men and children who, until 1994, lived in Kigali and the surrounding area. They were killed by the people around them – students by their teachers, patients by their doctors, neighbours by neighbours. Their stories remind us just what human beings can do to each other.

But they also remind us – and I am grateful that we have the opportunity to remember this here today – that the international community failed in Rwanda. Because it did not want to see what was happening. In Germany the massacres were initially described – with unmistakeable racist undertones – as, and I quote, “tribal feuds”, sometimes also as fighting “in the bush” – as if it all had nothing to do with us, as if human lives were not at stake. As if it had not been the colonial powers, including the German colonial administration, in the 20th century that had helped divide Rwanda more and more into allegedly ethnic categories of Tutsi and Hutu.

The painful truth is that clear signs of the bloodbath to come were visible long before April 1994: the militia training camps, the machetes distributed throughout the country, the hatred and incitement spread on the radio, and in particular the attacks on women and teenagers, the mass rapes, conducted on a systematic basis. But despite all that, not even the 2500 UN peacekeeping troops reacted to these alarm signals, because their mandate did not allow them to intervene resolutely enough to prevent the violence.

For us, for me as German Foreign Minister, the main lesson from Rwanda is that we bear responsibility both for our action and for our inaction.

Sometimes that makes things difficult, because we only become wise after the event. And so, again and again, we must face up to dilemmas, make decisions, even if they are difficult, and weigh up the consequences of our action or inaction. And we must respond more quickly if there are signs of an escalation of violence.

That is why we have learnt lessons over the last 30 years and corrected mistakes from the past. That is why Germany today invests much more in crisis prevention and early crisis detection. The Federal Foreign Office has established its own unit that analyses mass data, draws up risk analyses and plays out crisis scenarios. We engage in anticipatory humanitarian assistance in order to prevent even worse suffering. That is why I say today - because we have to look very closely - that our own failure 30 years ago must not lead to us looking away now when we see warning signs; rather, we must remain alert all over the world, not least in that region now, in face of the increasing escalation of violence in eastern Congo.

And, partly as a result of the lessons learned from the genocide in Rwanda, we have undergone a complete change in mindset. We have understood that it is also in our own interest to work for a world in which the strength of the law prevails, not the law of the strong – because this law, these values, are in our interest, as they make our own lives safer.

That’s why the second lesson to be learnt from Rwanda for us as the Federal Republic of Germany is that seeing what’s happening also means not allowing perpetrators to go unpunished.

The International Criminal Tribunal for Rwanda, on behalf of the Security Council, convicted 61 perpetrators. Decades later, here in Germany, another perpetrator was convicted at Frankfurt Higher Regional Court. That was new in the history of international criminal law. In Rwanda itself, the traditional Gacaca courts were revived to deal with thousands of cases. And that is our guiding principle today, the principle of universal jurisdiction, of prosecuting cases here – also following more recent genocides – if it is not possible to do so at the International Criminal Court.

Because that, too, is a positive lesson: if the victims and their descendants can be sure that the perpetrators will not escape unpunished, they can at some point forgive. In Kigali, on the terraces of the Genocide Memorial, you can feel even now how difficult this forgiveness is, how deep the scars run. However, you can also feel the great sense of hope that it is worth investing in reconciliation. High above the graves of the past, on a wall of the Memorial, there appears a sentence that to this day moves me when I read it. I quote: “If peace can be built after the Genocide against the Tutsi, it can be built anywhere.”