Brussels is marking ten years since the unprecedented lockdown of November 2015, a moment etched into the city’s collective memory as fear, uncertainty and silence overtook daily life.
The four-day shutdown followed the Paris terrorist attacks on 13 November, when 130 people were killed, and intelligence suggested Brussels could face a similar imminent threat.
On 21 November 2015, Belgian authorities raised the national alert level to four, its highest category, as police searched for Salah Abdeslam, the Belgian-born suspect believed to have played a key role in the Paris assaults. What followed was a capital city frozen in place.
Shops, cinemas, concert halls and cafés closed. Major commercial streets, usually buzzing on a Saturday ahead of the 6 December Saint Nicolas festivities, fell silent. Residents woke to find soldiers in flak jackets patrolling roads that would typically be overflowing with weekend shoppers and traffic.
For many, the eerie stillness was almost unbelievable. Some ventured out only to discover an empty city centre. Public life seemed to vanish, replaced by armoured vehicles and police operations sweeping across neighbourhoods.
The lockdown also revived memories of earlier attacks linked to radicalised militants.
In May 2014, Mehdi Nemmouche killed four people at the Jewish Museum in Brussels after returning from fighting with ISIS in Syria—an early warning of the cross-border networks behind the 2015–2016 attacks.
Both France and Belgium soon became central points in the investigation into ISIS-linked cells operating across Europe. Abdeslam fled Paris for Brussels after the November attacks, while Nemmouche was later arrested in Marseille after travelling by bus from Belgium.
Analysts say these incidents were not failures of Europe’s open borders but rather the effect of geography and long-standing mobility across the continent.
Criminal and extremist networks have moved between Belgium, France and beyond for decades, a pattern still seen today in drug-related violence linked between Brussels and Marseille.
The attacks of 2015 in Paris and in March 2016 in Brussels stemmed from a volatile mix: marginalised youth, radicalisation, racial hatred, access to weapons, and tragic chance.
Since then, Europe has seen a marked decline in major terrorist incidents.
Experts note that the biggest successes in counter-terrorism often remain invisible.
Neutralised plots or early interventions seldom make headlines, while failures, as seen in 2015 and 2016, leave an indelible mark.
Officials in Belgium and France credit years of improved intelligence sharing, community monitoring, and international cooperation for reducing the most serious threats. The anniversary also highlights the lasting gratitude expressed by the public — including a characteristically Belgian moment of humour.
During the 2015 lockdown, authorities urged residents not to post details of police operations on social media. In response, Belgians flooded Twitter with cat photos under the hashtag #BrusselsLockdown, a gesture that quickly went viral.
The federal police later posted a photo of a police cat bowl filled with kibble with the message: “For the cats who helped us last night… help yourselves!” The moment became a symbol of unity amid anxiety.
Ten years on, Brussels continues to evolve in its approach to security while carrying the lessons of those tense November days. The anniversary offers a moment of reflection not only on what was lost, but on what has since been prevented.
