Writing for the Focus on Africa magazine, Gill Lusk of Africa Confidential explores what common thread links the crises across the Horn of Africa
Mogadishu has not had a functioning government since 1991
The bloodshed in Somalia, where about 1,500 people were reportedly killed in Mogadishu alone in March and April, has attracted more international attention than for years, and is said to be as dangerous as at any time during its 16 years of turmoil.
The United Nations' top humanitarian official, John Holmes, declared the flight of hundreds of thousands of people from the capital the world's worst displacement emergency.
An estimated 2.5 million people are displaced in Sudan's Darfur region, but this has been over four years: in Somalia, most fled suddenly.
President Abdullahi Yusuf's transitional government is the outcome of endless meetings among Somalia's leaders: many spent two years talking in Kenyan hotels until donors pulled the plug.
One weakness of the administration is that not all members have the interests of their people at heart. The other side of this coin is that many warlords are now in government.
This is one reason why some Somalis, traditionally of a politically secularist bent, seem nostalgic for the Union of Islamic Courts (UIC) which took power in Mogadishu in June 2006.
Sudan's government blames the Darfur crisis on the West
And this is where the US comes in: the people the UIC captured power from were a collection of warlords gathered in the short-lived US-backed Alliance for the Restoration of Peace and Counter-Terrorism.
The warlords involved had often brought terror - though not Islamist terror - to Somalia and it was hardly surprising that many people welcomed the UIC takeover, which brought a semblance of peace.
However, it also brought Islamist politics - which set alarm bells ringing within Somalia itself and in neighbouring Ethiopia and Kenya, not to mention nearby Arab countries.
It was also a setback for the US, which has its regional spearhead in the "war on terror" - the Combined Joint Task Force-Horn of Africa - in Djibouti.
Washington has long maintained that some of the militants responsible for the August 1998 bombings of its Kenya and Tanzania embassies had taken refuge in Somalia, and in January, US forces bombed southern Somalia.
The US later admitted it had failed to "take out" any of its intended victims - although it had, of course, killed others.
The bombing was not in isolation: Ethiopia had just invaded Somalia to overthrow the UIC, which it did.
While Washington gave the green light for the invasion, Ethiopia is far from being a US puppet.
Prime Minister Meles Zenawi's government felt it had much to fear from the Islamists in Mogadishu.
It has long experience with its own Islamist rebels, including the Sudan-backed Oromo Liberation Front, and with the Islamist government in Khartoum, which was implicated in the attempt to kill Egyptian President Hosni Mubarak in Addis Ababa in 1995.
At the same time, both Ethiopia and Eritrea are pursuing a proxy war in Somalia on the principle of "my enemy's enemy is my friend".
The US is still seeking those behind the 1998 embassy bombing
Ethiopia has kept its armed forces in Somalia beyond the time promised, justifying this by a growing insurgency, which it has itself fed - this time from a mixture of Islamists, clan militias and nationalists.
But Eritrea is a main backer of this insurgency, having supplied armaments, money and training, especially to jihadis.
The tension in the region has allowed Sudan to pursue its own complex and Islamist agendas. This includes Darfur, where it has been accused of "ethnically cleansing" at least 200,000 of its own people.
The AU's peacekeeping efforts in Darfur have largely failed, while Khartoum has been resisting pressure for the deployment of UN troops.
Led by Egypt, Arab states have kept quiet, accepting the Khartoum line that the Darfur crisis is exaggerated and an age-old tribal and resource conflict - and, simultaneously, a Western/US/Jewish/Christian plot.
'Politics of fear'
And it may be a sign of the "war on terror" times that, while tens of thousands of displaced Darfuris have signed petitions calling for UN peacekeepers, many other northern Sudanese - who detest their own brutal Islamist government - believe its line that UN peacekeepers would be akin to the foreign invasion of Iraq.
Washington's approach to Islamism seems to involve containing, or attempting to contain, Islamist organisations while targeting individual terrorist suspects.
Western and Arab officials believe they have contained the NC in Khartoum and appear prepared to put up with the killing in Darfur.
Mogadishu is now being monitored by AU peacekeepers
The officials say they have no evidence of Khartoum's continued involvement in terrorism - it once harboured al-Qaeda leader Osama bin Laden - and claim security supremo Salah Abdallah Gosh is handing them invaluable secrets.
US forces in particular focus on "eliminating" specific individuals, though not necessarily successfully, across the Horn and Sahel belt while seeming to ignore the governments and organisations that spawned them - hence the attempt to kill the alleged planners of the Kenya-Tanzania embassy bombings through air strikes in Somalia.
In May, Amnesty International criticised the "politics of fear" which it said was "fuelling a downward spiral of human rights abuses".
It is clear that "war on terror" policies fuel a range of reactions, from simple anti-Americanism to jihad.
But governments that do not have to worry about democracy and human rights are manipulating the "war on terror" for their own ends.