What if the European Union will prove unable to guarantee European security?

At a time when America's physical presence in Europe can no longer make up for the uncertainty created by its mental absence, this question is crucial.

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To believe that security and defence could be made subject to the EU's community method is to ignore the fundamental nature of high politics. (Photo: German Marshall Fund)

Nato counts for very little without the US, and the Europeans alone are unable to guarantee the security order on which they rely.

With Nato's value put in question by US president Donald Trump's strategic malpractice and disregard for alliances, a frantic debate has sprung up among Europeans about who will keep them safe and free if America remains Awol.

For many European countries, albeit not all of them, the answer is, almost by default, the EU. This does not come as a surprise. After Nato, the EU is the second pillar of Pax Americana in Europe.

The EU itself nurtures the hope that it might be able to step in should Nato crumble.

It created fresh structures under acronyms such as Pesco, Card, and EFP to complement existing programs.

Its military staff is busy producing EU doctrine and the debate about liberalised defence markets is as old as the single market itself.

Juicy talk about "strategic autonomy", a European army, and "European sovereignty" is now the new normal in big ceremonial speeches about the EU.

One could get away with thinking Europe has finally woken up strategically.

But what if these were false hopes?

The widespread reluctance of European governments to actually spend on defence (and not just talk about it) and the underdeveloped strategic culture in EU capitals are bad enough, but they can be rectified over time.

The bigger question is whether there are more structural reasons why the EU is not the vehicle to serve Europe's increased military necessities in the 21st century.

Three such structural obstacle come to mind.

Compromise can be bought

First of all, the traditional mechanism of European integration as practiced by the EU does not lend itself to the field of security and defence.

The dirty little secret of EU integration is that most policy fields can be monetised to bring about compromise between member states. In other words: compromise can be bought.

Member states who teeth-grindingly acquiesce to an integration step they do not like will get rewarded for their approval elsewhere. Likewise, member states who do not want to play along on a certain item can, up to a point, buy themselves out of unwanted obligations.

Security and defence, however, is a field that cannot easily be monetised. As it is ultimately about survival, defence policy goes to the very core of what makes a nation.

The sovereignty bargains that make EU integration possible in other fields do not come easily to this one.

Defence also touches upon the centrepiece of a state's social contract with its people - legitimacy in return for protection.

Unlike in any other policy field, money is much less of a lubricant in this very fundamental deal.

In Nato, the nature of this policy field was acknowledged by excluding any military automatism in the Nato treaty.

Even when Article 5 on mutual defence is invoked each member state has the right, in accordance with its own constitutional provisions, to decide what it wants to do.

To believe that security and defence could be made subject to the EU's community method is to ignore the fundamental nature of high politics.

Secondly, for real integration in the field of security, large quantities of political trust are needed. But contrary to what most people believe, Europe today is what it has always been: a low-trust political environment.

Whether it is euro governance, post-colonial interests, relations with Moscow, fiscal prudence, links to Washington, defence spending, minority rights, or even old historic wounds, the picture is always the same: the French don't trust the Germans, Berlin distrusts Paris, and the Italians do not really trust either the French or the Germans.

And it is even worse than that.

The Germans do not trust themselves and England distrusts the continent, while Dublin distrusts London.

Warsaw also distrusts Berlin and Berlin distrusts Warsaw.

Central Europe distrusts Austria, the Romanians distrust the Hungarians, and in the Balkans nobody trusts anybody.

The South also distrusts the North, and the East distrusts the West.

When America was Europe's dominant power, old European rivalries were suspended and none of this mattered much. With America withdrawing, the old ill will returns to the European political market.

Lack of trust kills integration

In the field of security and defence, this lack of trust is a killer for any meaningful integration.

It is the reason why European nations do not really pool and share military assets or, if they do so, share only those parts that are the least relevant for national security.

As a consequence of Europe being a low-trust political market, the EU's political system was deliberately created as a leadership avoidance scheme.

The treaties were designed to deny any single member state political dominance within the club, military dominance not to mention.

Small countries were made comparatively big by the treaties, and vice versa.

The institutional compromise-making machinery was finely tuned to mediate power, keep things as technical as possible, and create package deals to enlarge the manoeuvring space for the balancing of interest.

Security and defence, however, benefits greatly from clear leadership.

It requires precisely what the EU so eagerly tries to avoid: big muscles, straight-forward and fast decision-making, hierarchical power structures and centralised operational authority.

Not only does the EU find it hard to deliver on these counts, it is unclear whether one should wish the EU to be able to do so. It would likely change the nature of the beast in rather unhealthy ways.

Naming the structural obstacles to meaningful European security and defence cooperation is not meant to discourage the debate.

Nato is still the preferred security vessel for almost all Europeans, but its future is unclear, and so Europeans must, nolens volens, bolster that second pillar.

They need to be aware what they are up against and their ambition must be much higher than what is observable today.

Only then will they be prepared for the painful debates that a securitisation of the EU will trigger and for the funding struggles that will take place once a broader audience realises that keeping Europe safe without America will be breathtakingly expensive.

And it must keep expectations low.

Because the only thing worse than an impotent EU is an EU that promises the world and then fails to deliver.