The demonstration was planned for 4pm on 15 April, a warm Sunday afternoon in the somnolent Nigerien capital. The protesters had two main complaints: rising taxes and the fact that, in recent years, some of the world’s most powerful armies had descended on their country.

But before the civil society leaders could even get to the march, they were arrested.

When a group of heavily armed men on motorbikes killed four American special ops soldiers in remote Niger last October, it was the first many had heard of the war the US was helping fight against a local branch of Isis.

But their involvement in that fight represents only a fraction of the US presence in the west African country, poor but strategically located in the middle of the Sahel, its borders crisscrossed by extremists and traffickers.

And the 800 US defence personnel in Niger are not alone. They are one of four western armies that have installed themselves in the vast desert landscape, variously flying armed drones, hunting militants, building vast bases, controlling migration and collecting intelligence from the region.

This is what the April protest was about.

Ibrahim Diori was arrested at home, and Maïkou Zodi in his car, both charged with participation in a banned demonstration and destruction of public property, even though they were not present. Today, they are in jail awaiting trial, along with colleagues arrested over previous marches.

The Nigerien government allows foreign powers free rein to build military bases and send soldiers to defend their interests in the region, while suppressing any dissent, according to those civil society leaders not in jail, and key opposition figures.

Facebook Twitter Pinterest Mariama Bayard. Photograph: Ruth Maclean/The Guardian

“Today there’s terrible repression of those who are against the government line. They put seven of my colleagues in prison because we said no to foreign bases,” said Mariama Bayard, leader of the opposition. She said that the government was “illegitimate” because the main challenger, Hama Amadou, was in jail at the time of the last election, and that it was being propped up by foreigners in the absence of domestic support.

“Dictatorship is taking hold of this country. The people don’t want the bases. But the Sahel has become an important geo-strategic space for the great powers,” she said.

According to Bayard, foreign powers do not have permission to build bases in their country.

“Our constitution says that before a base can be installed, parliament has to accept it. It’s a deal between the government and these foreign powers. It’s illegal, the bases are illegal.”

Facebook Twitter Pinterest Three giant white hangars of Airbase 201, Photograph: Tagaza Djibo/The Guardian

With Boko Haram in the south-east, Isis-linked ISGS on the Malian border, and a chaotic Libya to the north, Niger is surrounded by violent extremists.

As part of its counter-terrorism mission Operation Barkhane, France has 500 soldiers on its base in Niamey, and more on its bases in Madama and Aguelal. Germany has 50 soldiers in Niamey to support the UN peacekeeping force in Mali, and is expanding accommodation to cater for more on the airbase it shares with France. Canadian soldiers come and go.

Italy has an advance team of 40 soldiers in the country, preparing for the arrival of up to 430 more troops who will “train, advise and assist” local forces to fight illicit trafficking, mostly of migrants. Many of the 640,000 refugees who have arrived in Italy since 2014 came through Niger.

But it is the US, with its armed drones targeting militants including al-Qaeda leaders in Libya, that has attracted the most attention.

Niger is the perfect example of the US state of perma-war | Trevor TImm Read more

The three giant white hangars of Airbase 201, the new US base near the centuries-old city of Agadez, which is costing $100m (£78m) to build, stand on a long stretch of sand that is prone to puddles ; local herders used to take their goats to drink there in rainy season.

Some of these herders, living a few hundred metres away from the base’s new fences, said they had never met their new neighbours, though they often saw them whizzing past in air-conditioned SUVs, or by night, the shadow of their aircraft crossing the moon.

“They don’t help us. I’ve always been poor, and I’m still poor,” said Sedefiou Abdou, who had never heard of America until the base came to his neighbourhood. References to Obama, Trump and Coca Cola drew a blank. Then he was played a snippet of a French cover of the wildly popular Latin hit Despacito, and his face finally lit up in recognition. Apart from the airbase, this was the closest America came to penetrating into his corner of the Sahel.

Facebook Twitter Pinterest An image from Google Earth showing Airbase 201. Photograph: Google Earth

Abdou had no more need of this knowledge than most Americans do for Niger’s rich and complex culture; the two countries are thousands of miles apart. But his government and theirs were firm friends, as the Nigerien president said in an interview at his palace in Niamey, where former presidents deposed in Niger’s many coups gaze down from their portraits on the building’s high white arches.

“I don’t like the term ‘foreign forces’ – they’re friendly forces, who will leave as soon as we want them to,” said Mahamadou Issoufou. “They’re here at our request, and once the need for them disappears, they’ll leave.”

Facebook Twitter Pinterest Nigerien president Mahamadou Issoufou. Photograph: Tagaza Djibo/The Guardian

Issoufou recognised that they were also looking after their own interests, however.

“They’re not just here for us. They do it for themselves. The countries who have sent their armies know that once the Sahel is conquered, the threat will concern them, will concern Europe. It’s a way of preventing that threat from spreading into their territory.”

Niger is one of the most militarised countries in Africa. The government spends 21% of its small budget on defence, which means there is much less to spend on things like health and education. Hence the need for higher taxes, which the government says do not affect the poor but which have nevertheless sparked fierce opposition.

Civil society leaders and rights groups say protests against this and any controversial government policies have been “almost systematically denied”, while pro-government marches are allowed. Detained civil society leaders have been spread out in jails across the country, meaning their families struggle to visit and feed them; several were convicted of instigating an unarmed, banned gathering last month, and released having already served their time.

According to Boulama Hamadou Tcherno, one of the few civil society leaders who was not arrested in the March and April crackdowns, there has been silence from the nations in a position to put pressure on the government.

“We’re very worried about what will happen in the next few years. Freedom to demonstrate, freedom of religion – even praying to God is forbidden. And all the big democratic powers turn their gaze away.”

US special forces deaths in Niger lift veil on shadow war against Islamists in Sahel Read more

The Guardian put the allegations that America is in effect propping up an illegitimate and repressive government to Thomas Waldhauser, the head of US Africa Command, in an interview at a small American base in Senegal last week.

“They [Niger] have been a good partner of ours now for many years,” he said.

He emphasised that there had been “a lot of aid and security force assistance” in recent years and said that was why the US was there, as well as to help the country maintain its borders.

US troops should not be fighting in Niger, says President Issoufou Read more

Speaking more generally about the US presence in Africa, he said US troops were trying to “prevent something from spreading and happening before it actually does”.

According to opponents of the foreign bases, however, they do not stop terrorists but attract them.

“We see no results from their presence on the ground; in fact we have the impression that terrorism has increased since they arrived. Are they really here to help our soldiers?” Tcherno asked.

Bayard agreed. “They are creating the conditions for the Sahel to blow up,” she said. “They say that the bases are here for our security, but the opposite is true.”