A MQ-9 Reaper drone taxis at Kandahar Airfield, Afghanistan in this December 27, 2009 photo. (Efren Lopez/U.S. Air Force via Reuters)

The Pentagon has closed a drone base in Africa and moved the unmanned aircraft to other locations as it strains to cope with a surge in demand for drones from military commanders fighting the Islamic State and other militant groups.

The U.S. military has stopped flying unarmed Reaper drones from an airfield in Ethi­o­pia that had served as a key hub since 2011 for collecting surveillance on al-Shabab, an al-Qaeda affiliate in neighboring Somalia, U.S. officials said.

U.S. troops and contractors packed up the Reaper drones and dismantled their small base of operations in the southern city of Arba Minch in September. But the move was kept quiet until last weekend, when U.S. diplomats confirmed it in a report by an Ethio­pian news website.

U.S. officials were vague about why they decided to end the drone flights. Navy Lt. Cmdr. Anthony Falvo, a spokesman for the U.S. Africa Command, said the United States and Ethi­o­pia “reached a mutual decision that our presence in Arba Minch is not required at this time.”

Katherine Diop, a spokeswoman at the U.S. embassy in Addis Ababa, the capital, added in an email that “it is important to know that our presence in Arba Minch was never meant to be permanent.” A spokesman for the Ethio­pian embassy in Washington did not return a phone call seeking comment.

(The Washington Post) (The Washington Post)

The shutdown was unexpected. Just three months earlier, the U.S. Air Force signed a $6.7 million, three-year contract with an Ethio­pian tourist lodge to provide housing and office space for about 130 personnel who ran the drone operations, documents show.

U.S. military officials declined to say where, exactly, the drones have redeployed. But the move comes as the Obama administration faces pressure to intensify counterterrorism operations in numerous countries, from Afghanistan to Cameroon.

Those operations have been constrained in part by a severe shortage of military drone pilots and a tight supply of drone aircraft.

Drone pilots are in such high demand that the Air Force recently announced that it would award bonuses of up to $125,000 to entice them to stay in the military. The Air Force is also being forced to contract out more of its drone surveillance flights overseas to private companies.

The shutdown in Ethi­o­pia is part of a broader global realignment of drone operations, a critical component of the Obama administration’s counterterrorism strategy.

In October, President Obama said he would send 300 U.S. troops to another African country, Cameroon, to set up a new drone base and help local forces counter Boko Haram, a network of Islamic extremists that has destabilized much of West Africa.

It doesn’t appear that the U.S. drones from Ethi­o­pia were simply redeployed to Cameroon. U.S. military officials have said they are flying from Cameroon unarmed Predator drones, an older model than the Reapers that operated in Ethi­o­pia.

Meantime, demand is escalating for more drone flights elsewhere. The Pentagon has set up drone operations in another West African country, Niger, to conduct surveillance on Islamic fighters across a huge stretch of desert from Mali to southern Libya.

Several thousand miles to the east, U.S. commanders have been forced to keep more drones than expected in Afghanistan to deal with a resurgence of the Taliban as well as the re-emergence of al-Qaeda loyalists in parts of the country.

On top of that, the air war against the Islamic State continues to expand in Iraq and Syria, with drones playing a central role both in conducting surveillance and carrying out airstrikes. For that campaign, the Pentagon has bulked up its drone fleet at several bases in the region, including in Turkey, Kuwait, Qatar and the United Arab Emirates.

As it struggles to meet the increased demand, the Pentagon has been compensating by curtailing drone operations in Somalia and Yemen.

Although al-Shabab still represents a serious regional threat, U.S. officials and security analysts say that Somalia has gradually become more stable since the U.S. drone base in Ethi­o­pia opened in 2011.

African peacekeeping troops, financed largely by Washington, have taken control of Mogadishu, the capital, and chased Shabab fighters into rural areas. Meanwhile, several Shabab leaders have been killed in U.S. airstrikes.

The Pentagon continues to fly drones over Somalia from another regional base, in Djibouti, making the loss of the Ethio­pian base easier to take, said J. Peter Pham, an Africa analyst at the Atlantic Council, a Washington think tank.

“There’s less of a strategic reason to have a base there, so it makes sense to pack up and move to where there’s more of a need,” he said. “There’s been a great deal of progress [against al-Shabab], or at least as much progress as one can get from a drone program.”

A few weeks after it ended its operations in Ethi­o­pia, the U.S. Air Force also deactivated a Predator drone squadron based in Djibouti. The unit, the 60th Expeditionary Reconnaissance Squadron, was originally set up to fly missions over Yemen and Somalia.

During its last year in existence, however, the squadron was reassigned to focus on faraway targets in Iraq and Syria as part of the campaign against the Islamic State, according to a detailed report published last month by TomDispatch, a blog affiliated with the Nation Institute.