Jeremy Scahill has a must-read piece on the CIA's operations in Somalia, which may peripherally shed some light on why and how alleged al Shabab member Ahmed Abdulkadir Warsame was captured. According to Scahill, the U.S., through the CIA, has been running a local detention operation there under the auspices of Somali intelligence:
A Somali who was arrested in Mogadishu and taken to the prison told The Nation that he was held in a windowless underground cell. Among the prisoners he met during his time there was a man who held a Western passport (he declined to identify the man’s nationality). Some of the prisoners told him they were picked up in Nairobi and rendered on small aircraft to Mogadishu, where they were handed over to Somali intelligence agents. Once in custody, according to the senior Somali intelligence official and former prisoners, some detainees are freely interrogated by US and French agents. “Our goal is to please our partners, so we get more [out] of them, like any relationship,” said the Somali intelligence official in describing the policy of allowing foreign agents, including from the CIA, to interrogate prisoners. The Americans, according to the Somali official, operate unilaterally in the country, while the French agents are embedded within the African Union force known as AMISOM.
This might explain how Warsame was captured given the relative weakness of the local government and the absence of a large U.S. military presence.
One of the men supposedly being held in the Mogadishu prison is Ahmed Abdullahi Hassan, a Kenyan citizen the U.S. believes is working with al Qaeda who was rendered to the prison by Kenyan authorities. Scahill writes that his attorneys are planning to file a habeas claim:
Hassan’s lawyers are preparing to file a habeas petition on his behalf in US courts. “Hassan’s case suggests that the US may be involved in a decentralized, out-sourced Guantánamo Bay in central Mogadishu,” his legal team asserted in a statement to The Nation. “Mr. Hassan must be given the opportunity to challenge both his rendition and continued detention as a matter of urgency. The US must urgently confirm exactly what has been done to Mr. Hassan, why he is being held, and when he will be given a fair hearing.”
Gutteridge, who has worked extensively tracking the disappearances of terror suspects in Kenya, was deported from Kenya on May 11. The order, signed by Immigration Minister Otieno Kagwang, said Gutteridge’s “presence in Kenya is contrary to national interest.”
Whether or not Hassan is there, a habeas claim in U.S. courts seems likely to fail. U.S. Courts have rejected a right of habeas for prisoners at Bagram who were captured in third countries in the basis that the prison, despite being under U.S. control, is in an ongoing zone of military combat, arguing that this made Bagram different from Gitmo, where control over the territory itself is not contested. It seems unlikely that they'd accept a habeas petition filed on behalf of someone in a prison in a different country with an even smaller U.S. presence and one the U.S. can say is technically operating under Somali authority, even if Scahill's reporting suggests otherwise.
You should read the rest of the piece, which recalls that the current strength of al Shabab is a result of U.S. shortsightedness when it comes to the long term impact of its own counterterrorism policies. Scahill notes that the U.S. doesn't trust the local government and has been shoring up the international AMISOM force instead. The nagging question is whether or not in doing so, they're repeating a similar mistake to the one the Bush administration made in backing the U.S. backed Ethiopian invasion that made al Shabab what it is today.