France can help itself, but Nigeria needs support at this point...

It's a "brief" war, which is to say that media reports on the brutal, dehumanising violence as Boko Haram consolidates its hold on a nation-sized slice of Nigeria invariably are "briefs" because it is being fought in a "too" area – too dangerous, too remote, too far down any list of global priorities.

But satellite images released by London-based human rights group Amnesty International add weight to troubling speculation that Boko Haram, the African iteration of the so-called Islamic State which continues to run amok in Syria and Iraq, has just concluded its worst atrocity.

"These detailed images show devastation of catastrophic proportions in two towns, one of which was almost wiped off the map in the space of four days," said Daniel Eyre, Nigeria researcher for Amnesty. "Of all Boko Haram's assaults ... this is the largest and most destructive yet. It represents a deliberate attack on civilians whose homes, clinics and schools are now burnt-out ruins."

Nigerian authorities have played down an estimated death toll of as many as 2000 villagers, who are said to have been gunned down as they attempted to escape on foot or were incinerated while hiding in their homes, which were torched. But Amnesty describes the satellite imagery as "indisputable and shocking" evidence of the scale of attacks, the extent of which previously had to be extrapolated from witness accounts given over the phone.

By Amnesty's count, more than 3700 structures were damaged or destroyed. In Doron Baga, a town less than 4 square kilometres in size, about 3100 structures appear to be reduced to cinders or damaged; in nearby Baga, 2 square kilometres, the count is about 620.

Eyre explains another dramatic element in the images: "Many of the wooden fishing boats along the shoreline [of Lake Chad], visible in the image taken on January 2, are no longer present in the January 7 image, tallying with eyewitness testimony that desperate residents fled by boat."

Tactically, Boko Haram doubled-down after these attacks in Baga district, introducing a horrific new weapon to the conflict – child suicide bombers, as young as 10 and 15.

"I looked up and saw body parts everywhere, then the body of a little girl cut in two," a man who identified himself as Ibrahim Abu told reporters, in the wake of an explosion near an open-air cafe where he sat with friends in a market at Potiskum, south-west of Baga.

Describing himself to be paralysed by shock, he explained watching as the body of another child was pulled from the rubble, along with three others who were dead and 26 who were injured.

The embattled civilian population of Nigeria's Borno, Yobe and Adamawa states, in the north-east and abutting neighbouring Chad, Niger and Cameroon, faces double jeopardy – they suffer lethal attacks by Boko Haram, as punishment for what it says is their support for the national army; and they suffer lethal attacks by the national army, as punishment for what it says is their support for Boko Haram.

Worse, in the face of these most recent attacks, the national army fled, rather than stand to fight Boko Haram. More than 20,000 locals were abandoned to their fate.

A man in his 50s told Amnesty: "They killed so many people – I saw maybe around 100 killed at that time in Baga. I ran into the bush – as we were running, they were shooting and killing ..."

Another man described his own flight in fear: "For five kilometres, I kept standing on dead bodies ..."

A woman said: "I don't know how many, but there were bodies everywhere we looked."

Children and even a woman in labour were targeted in an indiscriminate rampage. Horrifically, a fourth witness recounted the death of the expectant mother – "half the baby boy is out and she dies like this."

When this latest shooting stopped at Baga, there was an echo of Boko Haram's abduction and sale into slavery of hundreds of schoolgirls early last year at Chibok, also in Borno state: the movement's fighters immediately combed the surrounding bush, rounding up women, children and the elderly.

A witness told Amnesty: "Boko Haram took around 300 women and kept us in a school in Baga – they released the older women, mothers and most of the children after four days, but are still keeping the younger women."

The violence, now at its most intense, started in 2009, when Boko Haram began lashing out at institutional and community power and symbols – the police, schools, churches, civilian enclaves and government buildings. Like Islamic State in Syria and Iraq, it wants a caliphate in which sharia law applies.

In the second half of 2014, it captured more than 20 towns in the north-east and also began launching attacks into Chad and Cameroon – killing thousands, displacing as many as 2 million Nigerians.

Boko Haram, translated as "Western education is forbidden" is the popular moniker for a movement more pompously known as Jama'atu Ahlis Sunna Lidda'awati wal-Jihad – which translates as People Committed to the Propagation of the Prophet's Teachings and Jihad.

There's a lot about modern Nigeria that makes it ripe for a movement such as Boko Haram.

There is its colonial history – and the lumping of separate Christian and Muslim populations into the one country; there's heightened poverty, in part a consequence of the collapse of its northern manufacturing base since Nigeria joined the World Trade Organisation in 1995; and there's a good bit of corruption and a fair bit of military cowardice.

The governor of Kano state, the British-educated Rabiu Musa Kwankwaso, told the Los Angeles Times last year: "There's a very strong correlation between poverty, unemployment, illiteracy and the issue of the insurgency and insecurity. A very poor man who is looking for something to eat can easily be recruited by the insurgents; and so can the unemployed and the illiterate, and that's exactly what's happening."

Despite fervent claims by government spokesman that the security forces have launched a counter-attack to retake Baga, locals say there's nothing happening – "it's all propaganda," one told CNN.

The extent of Boko Haram's grip on institutional power in Nigeria was underscored in 2012 when President Goodluck Jonathan observed that movement sympathisers were "in the executive arm of government; while some are even in the judicial arm. Some are in the armed forces, the police and other security agencies."

Last year 15 senior military officers were charged with passing intelligence and ammunition to Boko Haram and in the ranks, more than 50 went down on charges of mutiny and cowardice. Hence, there is deep reluctance in Washington and other Western capitals to share intelligence with Abuja and to provide weapons and ammunition to its security forces.

While world attention is tightly focused on Islamic State in Iraq and Syria and, to a lesser extent, the Shabab movement in East Africa, efforts to rally an international response to the Boko Haram rampage, in Africa and beyond, seem to have collapsed.

Niger was one of several countries that had responded to a French call for troops to be deployed to Baga district – but it withdrew them before the latest attacks. Heroically, a spokesman for the Niger government told reporters: "As you know Baga is under [the control] of Boko Haram terrorists and unless the town is recaptured from them, we'll not send back out troops."

Amidst the handwringing, University of Cambridge historian David Motadel cautions that when such movements have established their caliphates and confronted the workload of running a state, they might collapse in a heap – as they alienate their subjects.

Urging a containment strategy, he writes in The New York Times: "But given that the US and its allies are unlikely to commit the massive military resources necessary to defeat the Islamic State – let alone other jihadist states – the best policy might be one of containment, support of local opponents and then management of the groups' possible collapse."

Boko Haram's mass abduction of the Chibok schoolgirls was not the tipping point envisaged by some analysts – politically in Nigeria or policy-wise internationally. The world did respond – but only with outrage and a short-lived social media campaign.

It'll take more than a hashtag to turn the tide in Nigeria.