The Darfur conflict has killed up to 300,000 people, according to the UN, and has driven more than 2.7 million from their homes, some of them into neighbouring Chad, fuelling instability there. It ignited in 2003 as a political conflict between rebels in the western region and the Sudanese government in Khartoum but it was fuelled by longstanding competition between mostly Arab nomads and African farmers for scarce water and land after years of worsening drought. Herders who were once allowed to graze their camels on farmers' land because their droppings helped fertilise the soil found themselves increasingly blocked by farming communities. Some of them became eager recruits for the janjaweed, the Arab militias backed by Khartoum who have spearheaded the brutal counter-insurgency. International attempts to broker a peace agreement have produced little in the face of a splintering of rebel groups and an aerial bombing campaign by Khartoum, which has hindered the deployment of a new multinational peacekeeping force of UN and African Union soldiers. Meanwhile a 4,000-strong EU force is deploying in Chad in an effort to stop the conflict spreading. Some experts have argued that Darfur represents an early example of a new wave of conflicts driven by competition for land and water in a world of increasing scarcity. High food prices, also a result in part of climate change, have also triggered unrest in nearly 40 countries.