The March 22^nd terrorist attacks at Zaventem airport in Brussels and in the city’s metro system have left 31 dead and 260 injured, many severely. As the immediate shock begins to fade and the mourning period continues, searching questions are being asked about the effectiveness of Belgian security and the wider implications for European cooperation in this area.

In particular, many members of the public are concerned about having such a high concentration of Muslim citizens and immigrants in their midst. They are also worried that Belgium has the world’s highest per capita number of returned jihadi fighters from Syria, estimated at 500. Otherwise, the public reaction to the attacks has seemed to produce a more unified country and has thus frustrated terrorists’ efforts to create fear, division, and overreaction from policymakers and the public.

About 20% of Brussels’ population is Muslim. While the vast majority are considered to be law-abiding and hard-working citizens, a significant minority concentrated in the Molenbeek and Schaerbeek areas of Brussels clearly harbor radical tendencies. A hard core of these individuals is prepared to carry out the kind of attacks seen in Paris last November and now in Brussels. The number of disaffected and generally unemployed young Muslim men who might fall into that category is causing particular concern.

In spite of considerable police and military presence on the streets, government predictions that an attack on Brussels was probable, and numerous police raids to root out potential Daesh (also known as the Islamic State) sympathizers, the attacks still occurred. Belgium is not unique in failing to foil such atrocities, even in Western countries with greater institutional capacity. The United States, Spain, the United Kingdom, and France have all suffered the same fate in recent years. Where Belgium is unique is that its highly decentralized government does not lend itself to launching successful intelligence operations against terrorists, though the Belgian federal police did arrest Paris attacks suspect Salah Abdeslam on March 18^th.

The Belgian authorities have also identified two brothers, Ibrahim and Khalid El Bakraoui, as the two bombers who detonated suicide vests at Zaventem airport and the Maelbeek metro station. There are reports that Khalid had been deported from Turkey last year to Belgium—confusingly later changed to the Netherlands—and that the Belgian authorities had been warned about him. A third man, Najim Laachraoui, is the subject of an intense manhunt.

It is possible that the Brussels attacks were brought forward as revenge for the Abdeslam arrest, but might have taken place at a later date regardless. What is known is that Daesh has claimed responsibility for the violence, which bears the hallmarks of organized terrorism rather than a spontaneous initiative.

The attacks have again illustrated that a heavy security presence on the streets might go some way towards reassuring the public, but it is not effective in foiling terrorists. The same applies to airport security. Conventional wisdom suggests that good intelligence is the most efficient alternative to this, but the Belgian intelligence services have been criticized as ineffective and might benefit from better cooperation with other national intelligence agencies. The degree to which this already occurs is, by its very nature, difficult to assess.

The violence also tell us something about terrorist tactics. Belgium is not the most obvious target for Daesh: Its forces are involved against the group in Iraq but not in Syria. However, the country is a soft target. It has had open or virtually open borders with neighboring countries since 1945; it is the center of the European arms trade; it has a substantial Muslim population; and it is the headquarters of the European Union, which gives it effective symbolism.

Public spaces, especially transport hubs such as airports and railroad stations, are also particularly vulnerable. Calls for controls on access to these spaces, as practiced in some countries, are unlikely to be followed because lines of people gathering outside such buildings also form an easy target. Terrorists are only too aware that there is a limited public appetite for ever tighter security. There are no simple answers to the balance to be drawn between civil liberties and security. But Belgians and other Europeans will certainly have to get used to a tighter scrutiny of identity.

Meanwhile, the response to the Brussels attacks in the wider international community, although sympathetic to the plight of its citizens, has been somewhat cynical. Belgium has been accused of being the richest failed state in the world. Travelers are being advised to avoid the country for the time being and certainly to avoid crowded places. Tourism and trade will therefore be affected, compounding the effect of the attacks. Figures published in the Belgian press have already put the cost of the attacks at €400 million ($450 million USD).

On the positive side, the Mayor of Paris, Anne Hidalgo, traveled to Brussels the day after the attacks as a gesture of support. Unlike the French government in the aftermath of the Paris attacks, the Belgian government has not opted for a lockdown involving the closure of schools and all public transport. People are being urged to take up their lives again rapidly, albeit with increased identity controls in institutions and public spaces.

The solidarity shown by Belgians of all communities has been remarkable. As is often the case when tragedy strikes, people forget their differences. Hospital services have performed to their typical high standards. Sports centers have been opened up to accommodate stranded airline passengers. Volunteers have been providing meals and other necessities. From a public standpoint, Belgium’s response has typically been admired.

Personal human tragedies aside, it is well established that the most devastating effect of terrorism of this nature is the erosion of democratic values. This is the ultimate aim of groups such as Daesh. If the reaction of the Belgian public is any indication, they will not succeed.

Richard Lewis is a Senior Research Fellow, Migration and Diversity, at the Institute for European Studies, Vrije Universiteit Brussel.