After the terrorist attacks in Paris, citizens returned to work displaying an remarkable degree of fortitude. Investors were equally stoic. France’s CAC-40 index was never down much more than 2%, ending just 0.1% lower for the day. London’s FTSE-100 index slipped by a larger, but still-measured, 1%, while Germany’s DAX index actually inched 0.1% higher.

A sad sign of the times, perhaps. Experienced investors have learned that, unlike the human toll, the financial ramifications of a terrorist attack can be short lived. While travel and tourism related stocks like airlines, booking sites and cruise line operators were effected across global markets.

While a downturn in travel stocks is a common, and typically transitory, reaction to threats and acts of terrorism, a more lasting effect could come from the economic impact of fearful consumers and tighter borders.

European economies and the institutions underpinning the European Union are in fragile condition anyway.  Refugees have put pressure on many countries.

It’s not just France that will suffer. The ability of the Islamic State to strike indiscriminately, and at will, means that consumers across Europe could pull in their horns. Anecdotal evidence suggests that British shoppers remained home over the weekend, unnerved by reports that additional security personnel had been assigned to patrol shopping areas in London’s busy West End and in popular shopping malls.

The damage to Europe’s Schengen zone, which allows freedom of movement amongst 26 European countries, may be longer lasting. A number of nations had already erected temporary border controls in the face of the unprecedented wave of migrants fleeing the Middle East and Africa.

Yet the efficient transfer of goods across national boundaries has been crucial in creating pan-European supply lines. Witness Airbus, which sources components from Spain, Germany and the UK (admittedly, not party to the Schengen agreement) for assembly at hangars in southern France. Gone are the days when manufacturers consistently shipped completed units for sale abroad. Border bottle necks could profoundly affect manufacturing industries across Europe, at a time when industrial production is barely expanding.

But it may be political risk that poses the greatest threat to European economic prosperity. Nationalist parties have been gaining ground across Europe, not least France’s own National Front. Anti-austerity messages resonate with voters keen to register discontent with all policies emanating from EU headquarters in Brussels, economic or otherwise.

These novice political parties have no experience in steering already-traumatised economies to safety. Look no further than Greece for an example of a new political grouping grappling with the implementation of financial reform, to the detriment of its people. The human cost of these terrorist tragedies is incalculable; a measurable economic toll is bound to follow.