What does it take to galvanise international action - and funding - for such a crisis? The great tragedy is that in South Sudan's recent history this situation is not an aberration but the norm. The last civil war lasted from 1983-2004 in which 2 million people died. The Darfur conflict, beginning in 2003, still burns away.
Walking into the CARE supported clinic in Pariang, I see a little girl with edema - her belly is swollen because she hasn't got enough to eat. It's been a long time since I've seen a child with edema, and I certainly didn't expect to see one in this part of the country. Of all the places that CARE supports health care, Pariang, in Unity state, has traditionally been the least food insecure.
The well of pain runs deep in many parts of Africa, and yet it is young people who offer the best chance for true conflict resolution, and lasting peace. Conflict-affected youth are often the most ambitious, the hardest workers. They want back what was taken from them: opportunity. They want an education and they want to earn a livable wage.
The rarity of these new, liberal democratic nations is illustrated by the speculation in the media and elsewhere that a newly independent Scotland would have a lot to learn from three-year-old South Sudan. The inference is clear: Establishing a fully functional government and the apparatus of the state is a phenomenally difficult task.
In few places in the world can one week include both artillery fire and riding a speedboat down the Nile. South Sudan is one of those contrasts. The view is amazing - an enormous river, lined with greenery, very few buildings and exotic birds fly alongside the boat. There are no hotels, resorts or many people at all.
Oxfam and other aid agencies are warning that rival groups in South Sudan are regrouping ready to resume violence once the rainy season ends this month. An upsurge in fighting would exacerbate what is already the world's worst food crisis and could lead to famine. The number of people facing dangerous levels of hunger is expected to increase by one million between January and March.
While the eyes of the world rightly look towards global crises in Iraq, Syria, Gaza, Ukraine and West Africa, there is a serious and worsening humanitarian disaster almost going unnoticed in South Sudan. It is deeply saddening to see a country that was once so full of hope for the future, now embroiled in such a painful and destructive war with itself. When I first visited South Sudan less than two years ago I was struck by the optimism and hope that filled the air but today it is an entirely different story.
Before this conflict started in December, there was no inspiring and unifying vision of what South Sudan could be. The hope and optimism that came with independence is gone. Instead, there is now fear, mistrust and disillusionment between the people of South Sudan. An amazing opportunity has been squandered. It may take years to re-build a sense of unity.
When I was 11 years old, I was forced to become a refugee in my own country, Rwanda. I could see how innocent children and mothers suffered from a conflict they have never started. People died including my own brother. Innocent children were massacred. From then on, I developed a spirit of giving justice to those who are helpless, giving a voice to the voiceless, giving protection to the most vulnerable.
This is not just a humanitarian imperative; it is in all our interests to act. In the globalised 21st Century conflicts are not easily contained by borders. As the Stern Review made clear, tackling climate change will ultimately be cheaper than allowing it to proceed unchecked. But it is the human cost of these crises, the children of Gaza, the homeless Philippines and the South Sudanese families who do not know where their next meal is coming from that really demand our action. The UK public have shown they are up to the task; it is time for world leaders to do likewise.