NAIROBI — Despite the cloudy sky, Wilson, 50, is wearing sunglasses and a baseball cap. His small cellphone never stops ringing. He cracks a few jokes, plays a little electronic music, laughs — anything to avoid thinking about what happened that day.

"It was around 10 in the morning," he recalls. "That's when I was told something had happened. I was in my garage. One of his friends, in Somalia, called me to tell me there'd been an attack."

Wilson takes his sunglasses off. He's silent. For a few seconds he even seems to stop breathing. And then the tears come. Mark, his son, was 22. He'd joined the Kenyan army in 2013, only to die less than three years later in the middle of the Somali desert, in an attack carried out on Jan. 15 by al-Shabaab, the region's al-Qaeda affiliate.

The attack attracted little coverage in Europe and elsewhere. Yet it was by far the deadliest suffered by AMISOM, the African Union's UN-approved peacekeeping mission in Somalia. That morning, in El Adde, Kenya lost as many troops as the French army has in the last 10 years of foreign operations. An estimated 150 soldiers, from a supposedly trained and hardened army, were killed.

So far, Kenyan authorities haven't given any official death toll. "They said it's because they didn't want to the public to panic," says an aggrieved diplomatic source in the Kenyan capital, Nairobi.

This is a national tragedy. The recruits were in their twenties. They came from all parts of the country, from the banks of the Victoria Lake to the slopes of Mount Kenya.

The jihadist group had carried out similar attacks in 2015, on bases in Lego and Janale. "The army knew such an attack could come. They simply refused to believe it," a Nairobi-based security expert says.

Created in 2007 to stabilize the country and fight against the jihadist threat, AMISOM is a mission of rare complexity that is compromised by its contradictory impulses. Officially operated by the African Union, it now has 22,000 troops (having started with 1,600), mostly from Ethiopia and Kenya, but also from Burundi, Uganda, Sierra Leona and Djibouti.

The mission has no helicopters and its soldiers are poorly equipped and inexperienced. Some of them don't even get paid, Professor Paul D. Williams showed in an edifying report published by the Heritage Institute for Policy Studies. AMISON troops have also been accused of mass rape and other abuses on the populations.

The mission is also marked by a tense rivalry between the Kenyan and Ethiopian components regarding the Somali pie. Several experts note that Ethiopian troops, located just 50 kilometers from El Adde, didn't so much as budge during the attack.

But none, or at least not very much of that, was talked about in Nairobi. The bodies were discreetly repatriated, often by night. Sure, there was a debate in parliament, but it took place behind closed doors. Speaking to the families of the victims, President Uhuru Kenyatta mechanically read a text condemning "mankind's enemies" and praising the "brave Kenyan patriots."

"Kenya will move forward," he concluded. Time to move past El Adde, in other words. Everything's fine and calm in Nairobi.

The newspapers reported what the army was saying, but without any real critical analysis. "There's been no investigation," says Patrick Gathara, a journalist for the Kenyan daily The Star, and one of the few reporters to have raised questions. "Most of the adverts in the newspapers are paid by state-owned companies or the government, so it's very easy to put pressure on them," he says.

Some bloggers and a few activists faced trouble for publishing pictures of the soldiers killed in El Adde. "If you express a different opinion than the army on Somalia, you'll be labeled suspicious, dangerous, like a traitor, pro-Shabaab and antipatriotic," Gathara says.

Families have also kept mostly quiet. "It seems they were given very strict instructions from high up not to talk to the media," a journalist who preferred not to be named explains.

So how is it possible to mourn in this environment of silence and denial? Like many other devastated parents, Wilson isn't quite there yet. In early April, the family celebrated Mark's birthday. They lit 23 candles for their lost son. As if he was still alive. As if he hadn't died for nothing.