“You cry like a woman because you couldn’t defend like a man,” said Muhammad XII’s mother as the weeping emir left the Alhambra Palace for the ceremony in which he surrendered to Spain, Islam’s last West-European realm.

That was in 1492. Now the pendulum has swung. As Muslims this week again sent Christian Europe running for cover, the one shedding tears was European Union foreign policy chief Federica Mogherini.

The attackers’ affiliation, motivation and aims became clear shortly after they murdered dozens and wreaked havoc in the EU’s capital: They were activated by Islamic State, which in turn explained through its news agency that it was out to attack “the cross-bearing nations”—meaning Christendom—and that it has in store for them “black days” that will be much worse than what Europe has so far endured.

French President François Hollande’s statement following November’s attacks in his country “France is at war” this week became “Europe is at war.”

The Islamist war on Europe has now reached the very headquarters of the EU, shaking the flagpoles that line it, shortly before a major EU member—Great Britain—issued a travel warning to the EU’s capital.

Few measures could vindicate more harshly the growing suspicion that the EU is a failed experiment, and that the Muslim challenge that has been the doing of many European governments will be their union’s undoing.

The current Muslim challenge evolved over nearly three generations, after Western Europe opened its gates to the immigration it has largely failed to absorb.

Historically, however, Europe and Islam have been at loggerheads intermittently since the eighth century, when Muslim armies conquered Spain and then invaded France through the Pyrenees before landing in Italy and reaching Rome.

Consequent Muslim rule, from Barcelona to Sicily, may be trivial to current-day Christian Europeans, but to some Muslims it is a recollection both vivid and instructing. Similarly, the Ottoman conquests at Europe’s other end remain traumatic memories in Greece, Bulgaria, Serbia and Hungary.

Now this legacy of disharmony is returning to the fore.

Yet unlike previous Muslim penetrations into Europe, which followed military conquests, the current presence follows a mostly peaceful immigration whose causes and results bring to mind not medieval Europe’s struggles with its Muslims but ancient Rome’s decline and fall.

Before Rome was “delivered to the licentious fury of the tribes of Germany and Scythia,” as Edward Gibbon put it in “The Decline and Fall of the Roman Empire,” the number of Romans joining its army was steadily declining; the middle classes were overtaxed to finance grandiose public works; the cities that once were the empire’s social backbone were crumbling under the weight of foreign migrations; a hedonistic elite increasingly shunned politics; and a new religion’s believers threatened the social, political and cultural order.

Much of this has been happening in Europe, gradually but steadily, in recent decades.

Like ancient Rome, Europe has effectively opened its doors to an underprivileged workforce that brought with it a triumphalist faith’s zealots, while the Europeans themselves had fewer children, worked shorter hours, paid high taxes for grand public works and demanded of their citizens less and less military duty.

Europe’s porous borders and vulnerable currency are now suspected by a growing number of its citizens as part of this syndrome of political weakness and self-inflicted vulnerability.

All this was at work, and already festering, well before this decade’s tumult in the Middle East. Now, with the Arab civil wars’ refugees sailing to its shores in droves, it seems the challenge Europe faces picks up from where Rome’s demise and Islam’s assaults left off.

As long as this sort of historic perspective is not considered in the very Brussels that has just been targeted, Europe will remain on the defensive, its enemies’ gains will accumulate, and their Christian victims will grow increasingly restless, insecure and, ultimately, also violent.

What, then, should Europe do?

The first thing Europe must do is define the enemy.

Calling the enemy “terror” is not only misleading but also disorienting.

Terror is not the enemy, but the enemy’s weapon. The enemy is Islamist fundamentalism, the ideology that feeds the terrorists and lets Europe’s blood.

The second aim must be to restore the political vitality that the EU has unwittingly damaged.

In this regard, the worst damage has been done by the launch of the euro, an unworkable currency that imposes strong economies on weak ones, first granting them financial presents, then bilking them, and in the interim nurturing their escape from responsibility.

Fighting the war that Europe faces demands a restoration of political responsibility and clout, and this can be accomplished only by governments that tax directly and spend independently.

That means that the governments that choose to continue sharing the euro will have to create a fully unified budget and taxation system. The rest will have to leave it and restore their previous currencies.

This will be difficult surgery, but it will restore the understanding that all Europeans—citizens and governments alike—are returning to the business of self-help.

At the same time, there will have to be an overhauled security attitude and reallocation of resources.

This process has already begun in France and Britain, where military, police and intelligence budgets have been bolstered in recent months after years of deep spending cuts. Still, as the whole world saw this week, administrative apathy and lethargy remain a major problem for European security.

Preventing the arrival of weapons and explosives into bustling terminals requires not only the positioning of more metal detectors, though that, too, was glaringly missing in Belgium. It demands thousands of detectives scrutinizing around the clock what thousands of ubiquitous cameras unveil, while plainclothes agents roam the potential paths of potential troublemakers.

Enlisting and deploying all this will cost a fortune, but that is what Europe must do if it is to defeat the Islamist enemy it faces. This will also entail an intrusiveness that will compromise civil freedoms, as has long been understood in the US, not to mention Israel.

In the same vein, Europe will have to retreat from its open-borders utopia.

The mental transition this will require is much like that which Israel underwent last decade before building the anti-terrorism fence. Initially opposed by both Israeli utopias—those who feared it would compromise Greater Israel and those who feared it would monumentalize the Oslo peace vision’s failure—the fence still arose because the people imposed it on the politicians.

Europe’s felled fences already are effectively being rebuilt, also due to pressure from below, in Hungary, Austria and Bulgaria, while border controls are resurfacing between Denmark and Sweden.

Britain’s travel warning to Brussels this week was also a form of restoring Europe’s internal borders.

There will be more of all this in upcoming years, even if Britain does not vote to leave the EU in its June referendum, let alone if it does.

The restoration of borders is but the beginning of the broader mental transition that more and more Europeans will demand, and their leaders will have to deliver if they are to survive politically. This effort will have to face both inward and outward.

Inward, Europe will have to tell its people that they are at war and that they must personally join it.

That will mean expanded conscription to the security forces, creating civil-guard volunteer organizations that will help protect public places, and also persuading young couples to have more children, because Christian Europe’s demographic crisis leads to the kind of social degeneration that undid ancient Rome.

Outward, Europe will have to enter the neighborhoods, minds and hearts of its Muslim immigrants and fight there for its convictions, both physically—by locating its enemies and treating them as such—and educationally, by instilling its ideas and convictions.

That is what its Islamist enemy has been doing day in, day out, year after year, while Europe exposed its borders, diluted its money, compromised its work, and had fewer and fewer kids. For without restoring a sense of public purpose, political authority, personal responsibility and social vitality—Christian Europe might be doomed.

By Amotz Asa-El/Jerusalem Post