THE HORN of Africa is suffering from its worst drought in 60 years, and food shortages are affecting as many as 12 million people across the region. Not surprisingly, however, the greatest emergency is in southern Somalia, an area under the control of al-Shabab, a group of Islamic militants allied with al-Qaeda. The United Nations has declared that two regions are suffering from famine conditions, with child malnutruition rates of up to 55 percent and infant deaths of six a day. An estimated 2.8 million people in southern Somalia are facing starvation, and 3.7 million in the country overall — or half the population.

Notwithstanding the drought, much of this misery is man-made. Al-Shabab has driven out Western aid groups, which have not operated in southern Somalia since early 2010. It has waged perpetual war against the Somali government and U.N. peacekeeping forces. It has killed Western aid workers. According to a report in the New York Times, it has diverted water resources from poor farmers and imprisoned starving people trying to escape the country.

The outside world has been slow to address this crisis. Early warnings of a famine began last November, but the U.N. declaration did not come until late in July. At that point only about half of the aid requested by international agencies had been pledged. Probably only an international military intervention could prevent mass starvation, but having tried just that in 1992, only to suffer casualties it was unwilling to accept, the United States has no appetite for such a mission. A U.N. force deployed in Mogadishu can barely keep the small swath of territory controlled by the internationally recognized government from being overrun.

The alternative to intervention is to loosen restrictions that have hampered U.S. aid to groups operating in al-Shabab-controlled areas. The movement has been designated a terrorist organization; U.S. aid to Somalia dropped by some 80 percent between 2008 and 2010. According to The Post’s Mary Beth Sheridan, Secretary of State Hillary Rodham Clinton has been working on ways to ensure that aid groups working in Somalia will not face prosecution if they are forced to pay bribes to al-Shabab or if militants divert some food supplies. State Department officials said Tuesday that they were seeking to reassure aid groups that they could deliver food and medicine without running afoul of the law.

That would still leave aid groups with the problem of gaining access to famine victims and ensuring the safety of their personnel, a number of whom have been murdered by the militants. But the crisis may be causing al-Shabab’s cohesion to break down; some commanders have been cutting deals with aid organizations to receive food supplies.

The only durable answer to Somalia’s famine is the establishment of a government that can control the entire country and that respects basic human rights. Sadly, there is little prospect of that. But the United States and other Western governments must do what they can to prevent mass starvation.