The newest outpost in the US government’s empire of drone bases sits behind a razor-wire-topped wall outside Niamey, blasted by 40C heat and the occasional sandstorm blowing from the Sahara.

The US air force began flying a handful of unarmed Predator drones from here last month. The grey, mosquito-shaped aircraft emerge sporadically from a borrowed hangar and soar north in search of al-Qaida fighters and guerrillas from other groups hiding in the region’s deserts and hills.

The harsh terrain of north and west Africa is rapidly emerging as yet another front in the long-running US war against terrorist networks, a conflict that has fuelled a revolution in drone warfare.

Since taking office in 2009, President Barack Obama has relied heavily on drones for operations, both declared and covert, in Afghanistan, Iraq, Pakistan, Yemen, Libya and Somalia. US drones also fly from allied bases in Turkey, Italy, Saudi Arabia, Qatar, the United Arab Emirates and the Philippines.

Now they are becoming a fixture in Africa. The US military has built a major drone hub in Djibouti, on the Horn of Africa, and flies unarmed Reaper drones from Ethiopia. Until recently, it conducted reconnaissance flights over east Africa from the island nation of Seychelles.

The Predator drones in Niger, a landlocked and dirt-poor country, give the Pentagon a strategic foothold in west Africa. Niger shares a long border with Mali, where an al-Qaida affiliate and other Islamist groups have taken root. Niger also borders Libya and Nigeria, which are also struggling to contain armed extremist movements.

Like other US drone bases, the Predator operations in Niger are shrouded in secrecy. The White House announced in February that Obama had deployed about 100 military personnel to Niger on an “intelligence collection” mission, but it did not make any explicit reference to drones. Since then, the defence department has publicly acknowledged the presence of drones here but has revealed little else. The Africa Command, which oversees US military missions on the continent, denied requests from a Washington Post reporter to interview American troops in Niger or to tour the military airfield where the drones are based, near Niamey’s international airport.

Government officials in Niger, a former French colony, were slightly more forthcoming. President Issoufou Mahamadou said his government invited Washington to send surveillance drones because he was worried that the country might not be able to defend its borders from Islamist fighters based in Mali, Libya or Nigeria.

“We welcome the drones,” Mahamadou said in an interview at the presidential palace in Niamey. Citing the “feeble capability” of many west African militaries, he said Niger and its neighbours desperately needed foreign help to track the movements of guerrillas across the Sahara and Sahel, an arid territorial belt that covers much of the region.

“Our countries are like the blind leading the blind,” he said. “We rely on countries like France and the United States. We need co-operation to ensure our security.”

The Predator drones in Niger are unarmed, US officials said, though they have not ruled out equipping the aircraft with Hellfire missiles in the future. For now, the drones are conducting surveillance over Mali and Niger.

US officials said they share video footage and other intelligence collected by the unmanned aircraft with French forces and African troops – including 670 soldiers from Niger – who are fighting the Islamist insurgency in Mali. Liaison officers from Niger, France and Chad work alongside US air force personnel who launch and land the drones from the base in Niamey.

Most of the surveillance missions are designed to track broad patterns of human activity and are not aimed at hunting individuals, said a senior US official, who spoke on the condition of anonymity to discuss military operations. Although French and African troops are engaged in combat in Mali, the Obama administration has not given the US military the same authorisation.

“The whole issue is lethality,” the senior official said. “We don’t want to abet a lethal action.”

But the rules of engagement are blurry. Intelligence gathered by the Predators could indirectly help the French fix targets for airstrikes or prompt Nigerien security forces to take action on their territory.

Moreover, US officials have acknowledged that they could use lethal force under certain circumstances. Last month, army general Martin Dempsey, the chairman of the Joint Chiefs of Staff, told Congress that the US military had designated “a handful of high-value individuals” in north Africa for their suspected connections to al-Qaida, making them potential targets for capture or killing.

The Pentagon declined to say exactly how many Predator aircraft it has sent to Niger or how long it intends to keep them there. But there are signs that the US military wants to establish a long-term presence in west Africa.

After years of negotiations, the Obama administration signed an agreement with Niger in January that provides judicial protection and other safeguards for US troops in the country.

Two US defence officials, speaking on the condition of anonymity to discuss internal planning, said the Pentagon ultimately wants to move the Predators to the Saharan city of Agadez, in northern Niger.

Agadez is closer to parts of southern Algeria and southern Libya where fighters and arms traffickers allied with al-Qaida have taken refuge. The airfield in Agadez, however, is rudimentary and needs improvements before it can host drones, officials said.

The US military has used Agadez since last year as a refuelling stop for U-28 spy planes – small, piloted aircraft flown by private contractors. US officials have hesitated to send those surveillance aircraft across the border into Mali because of fears that the crews could be taken hostage if the planes crash or are shot down.

Government officials in Niger declined to say whether they viewed the US drones as a short-term fix or a permanent addition. “I can’t tell you how long they will be here,” said Mahamadou, the president. “How long it will take to stabilise Mali is one factor. The stabilisation of Libya is another.”

At the same time, he said Niger cannot rely on French and US military forces forever and needs to ensure its own security. To that end, the US government has agreed to give Niger two Cessna Grand Caravan aircraft to transport troops and conduct surveillance.

“The intelligence is crucial for us,” said Colonel Mamane Souley, director of exterior relations for the Nigerien armed forces. “We have a vast territory, and in that sense aircraft are fundamentally important.”

The presence of hi-tech Predator drones in Niger’s skies contrasts jarringly with life on the ground. There are only a handful of paved roads in the capital. Many people live in mud-brick shanties. Goats and camels are a common sight in the city centre.

US and Nigerien officials had worried that the drones might spur a popular backlash in Niger, where about 90 % of the population is Muslim. Extra security barriers were raised outside the US and French embassies as a precaution. So far, however, reaction has been muted, and many people seem to favour anything that the US and French militaries can do to prevent a spillover of violence from Mali.

“Of course, we might have some narrow-minded Nigeriens,” said Marou Amadou, who serves as justice minister and chief government spokesman. “But people understand that the presence of these drones is very, very helpful … What is happening in Mali could happen in Niger also.”

Nonetheless, US troops have kept a low profile. Americans with short haircuts and a military bearing occasionally surface at a couple of Niamey hotels to eat barbecue or drink beer, but most confine themselves to the base.

The Africa Command did not respond to questions about how many US troops are in Niger, but one US official said the number of air force personnel had increased beyond the 100 troops Obama said last month he had deployed.

“We just know there are drones; we don’t know what they are doing exactly,” said Djibril Abarchi, chairman of the Nigerien Association for the Defence of Human Rights, an independent watchdog group. “Nothing is visible. There is no transparency in our country with military questions. No one can tell you what’s going on.”

Most Nigeriens are strongly opposed to al-Qaida in the Islamic Maghreb, the terrorist network’s affiliate, and recognise that their country is vulnerable without foreign military help, said Boureima Abdou Daouda, an imam in Niamey who leads a regional council of religious leaders that advises governments on countering extremism.

At the same time, as in many African countries, the presence of foreign troops is a sensitive issue given the history of colonialism in Niger. Daouda warned that the government could face trouble if it doesn’t shore up popular support and do a better job of publicly explaining why the American drones are necessary.

“Someone with bad intentions could say, ‘They are here to cause strife with Muslims’,” he said. “People might demonstrate. They might riot. Big flames begin with little flames.”

(This article appeared in the Guardian Weekly, which incorporates material from the Washington Post)