After all, Schengen is one of the key pillars of the European project and its dismantlement would herald the end of one of the most successful and visible achievements of the EU.

The far-right candidates have had competition in this year’s high-stakes elections: in France, even some mainstream conservative candidates depicted the Schengen zone as a threat to national security and the control of migration – advocating for the return of border controls within the Schengen area or its wholesale elimination.

While these populist stances are part of a transatlantic nationalist narrative that also echoes from the White House of US president Donald Trump, they are based on several fundamental untruths.

The main untruths

First of all, with highly secured passports and a standardised control process for travellers coming from non-Schengen countries, the external borders of the EU (and non-EU Schengen countries: Switzerland, Norway and Iceland) are as secure as any other.

Despite widespread fears of foreign terrorists disguising themselves as refugees to cross into Europe, not one of the perpetrators of the terrorist attacks over the last two years fit this alleged profile.

Whether in France, Belgium, or Germany, those responsible for these horrendous acts of terror lived in Europe for years prior – and, in most cases, their whole lives.

Secondly, the argument that open borders are a drain on national economies is patently false.

In reality, from an economic point of view, the disintegration of Schengen would have catastrophic effects – jeopardising trade and growth, and increasing unemployment.

A recent study by the French Commissariat for Strategy explained just how much: “In the longer run, widespread permanent border controls would decrease trade between Schengen countries by a factor of 10% to 20%”.

The study added that “this would be equivalent to a 3% value-added tax on trade, leading to a loss for France of half a percentage point in GDP, or more than €10 billion. This figure does not include the impact on foreign investment and labour mobility.”

It also outlines the impact it would have on the Schengen area’s overall economy: “Overall, the Schengen area’s GDP would be reduced by 0.8 points, equivalent to more than €100 billion. An additional impact on labour mobility, foreign investment and financial flows can be anticipated, but is difficult to quantify.”

Opening France

Voters in France were perfectly cognisant of the importance of Europe’s open borders when they went to vote earlier this month.

Freedom from internal border controls has a major impact on tourist flows, boosting an industry critical to the economies of many EU countries. This not only includes short-stay travellers, but also those coming from outside the Schengen area as part of a longer trip.

By making it easy to visit multiple countries during the same trip – and sparing tourists the burden of multiple national visas – freedom of movement helps spread tourist euros across the EU.

Schengen also facilitates regular cross-border movement for millions of Europeans: in France alone, 353,000 people worked in a neighbouring country in 2011.

For these workers and others, including those who work in Europe’s freight industries, a return to border controls would be economically disastrous.

Most importantly however, losing Schengen would signal a dramatic loss of political capital for the EU – fatally undermining the four basic freedoms of persons, capital, services, and goods.

Internal borders and controls are unwelcome vestiges of the old Europe; a continent without borders is a highly political and symbolic asset, especially when compared to the barbed-wire fences being erected in some corners of the world. It also encourages non-Schengen EU countries (such as Romania and Bulgaria) to join the area.

Beyond pure economics, Schengen embodies fully-fledged membership and integration into the EU. By governing institutional arrangements made with outside countries, Schengen has also become part of the EU’s soft power.

Reduce borders, increase power

For Eastern bloc countries and other emerging democracies around the world, visa-free access to the Schengen area is a prized objective.

Ukraine just received final acceptance from the European Parliament in April 2017, a significant milestone after the 2014 Maidan revolution in the country that was driven by European values.

Schengen has also served as a useful bargaining chip in bilateral negotiations outside Europe.

Peru, for example, recently celebrated one year after having lifted Schengen visa requirements for its citizens. That newfound access was facilitated by Peru’s new, fully secured biometric passports from France’s Imprimerie Nationale and Gemalto, which prevent fraud and contribute to the fight against falsified documents.

Paradoxically, while some nationalist European parties are openly considering abandoning the Schengen model, other regional blocs are thinking of embracing it: the Gulf Cooperation Council and ASEAN have just been the latest to seriously consider lifting internal border controls.

By exploiting latent fears of uncontrolled immigration across open borders, far-right parties such as the Danish People’s Party, France’s Front National, and the UK Independence Party (Ukip) have managed to turn the Schengen area into a political hot potato despite its manifold benefits.

Macron’s victory in France has temporarily neutralised this political threat, but he himself has repeatedly assessed that the work is not over.

An open Europe must successfully protect its citizens against terrorist threats, aggressive powers, and internal dumping.

Otherwise, the narrative being pushed by illiberal and anti-European populists will regain traction sooner rather than later.

Nicolas Tenzer is the chairman of the Paris-based Centre for Study and Research for Political Decision (Cerap), editor of the journal Le Banquet, author of three official reports to the government, including two on international strategy, and of 21 books.