This is the new and uncomfortable reality that European leaders now have to accept and respond to. It is a reality that is not going to go away as long as the so-called Islamic State, al-Qaeda, and their battalions of supporters inside and outside Europe continue their mission to attack everything that Europe stands for. It is Europe’s liberal values and open society that the perpetrators of these attacks, many of them born in Europe, are taking advantage of. Those values are now at stake.

Proclaiming that Europe stands by its values in the wake of the terrorist attacks is all very well. But the rhetoric will not make Europe’s citizens feel any safer, nor will it deter more bombers. European leaders face the uncomfortable but necessary task of dealing with a war that wants to destroy what Europe stands for.

Until now, in most cases European governments have found neither the means nor the political will to stop these attacks. For some reason, the attacks were never appalling enough to jolt Europe out of its belief, or blindness, that its values alone would protect a special way of life.

The Brussels attacks have shattered those illusions. Protecting values and dealing with war are almost a contradiction in terms. But European governments could weaken this contradiction in a number of ways.

The first is with better security. The EU and its member states have long refused to make intelligence sharing a major priority. There were many reasons for this. Intelligence agencies don’t want other agencies trampling over their turf. Some governments see sharing information as an infringement of their sovereignty. It is time to put these considerations to rest. If European citizens can crisscross borders, then the logic should follow that the intelligence agencies can do the same.

The advantages are clear. So are the disadvantages. The political culture of Europe’s intelligence agencies widely differs; so do their snooping powers and what they can do with that information.

Defenders of data protection and opponents of data sharing will understandably rush to keep the national laws as tight as possible from the reach of the agencies. They will also argue that intelligence agencies will snoop on innocent people. Look at the controversy raging around Apple’s determination not to unlock data stored in the mobile phones of the terrorist couple who killed several people in San Bernadino in 2015 or how U.S. and European agencies spy on each other. But the issue of intelligence sharing has to be tackled head-on, and now.

Another issue is public security. The public, unfortunately, will remain a target, and security services somehow need to find a way to make citizens more secure in public places. It is an enormous challenge and an enormous balancing act. Compromises will have to be made.

But the biggest issues that EU governments have to deal with are migration and integration. Populist and Euroskeptic parties across Europe were quick to exploit the attacks in Brussels as if these atrocities had vindicated their stance. Their stance is worrying and often anti-liberal, particularly when it comes to social issues.

But that is just the tip of the iceberg. These parties are anti-foreign—frankly, anti-Muslim—and as a corollary, against migration. They do not believe in the integration of large Muslim communities. Above all, they support a strong state. A Europe that has more security, more controls, more surveillance, and more state power has the potential to tap into the authoritarian tendencies of populist movements. That is an issue that has to be taken seriously.

As for integration, it is easy to forget the many Muslims living in Europe who have set up successful businesses, adopted European norms, and despise what is happening in the name of their religion. It is only a tiny minority that is sowing the seeds of hatred, violence, and fear and that exploits those who feel socially, economically, and politically marginalized. More certainly needs to be done across Europe so that the younger generations have greater opportunities for social advancement.

Of course, populist movements don’t see it that way. Instead, they are sapping support from people who fear globalization, who fear unemployment, who feel the political elites have forgotten them, and who believe immigrants will make matters even worse.

It is going to take an enormous effort by European governments to tackle and define integration. EU leaders will have to eschew political correctness by asking awkward questions about what Europe stands for and why terrorists are attacking those values.