Euro 2016 organizers insist the Paris terror attacks will not disrupt next year's 24-team tournament across France and that security will ensure spectators will be able to visit matches without fear.
"We will take the necessary steps so that Euro 2016 takes place with the best possible security measures," tournament organizing chief Jacques Lambert insisted.
Yet Friday's terror attacks across Paris including an apparent attempt to carry out suicide bombings inside the Stade de France make it difficult to believe a joyous summer football festival is now possible.
The 51-match tournament is set to take place from June 10 to July 10 in nine French cities - Paris, Bordeaux, Toulouse, Lille, Lens, Lyon, Marseille, Nice and Saint-Etienne.
A million tickets have already been sold in a first sales phase, with European governing body UEFA beginning another sales phase in four weeks.
Twelve matches will be played at two venues in Paris - the Parc des Princes and Stade de France - with the tournament opener and final at the Stade de France in Saint-Denis just north of Paris.
The three loud detonations heard inside the stadium during France's friendly match against Germany brought terrorism right to Euro 2016's door.
Security officials believe three suicide bombers tried to get into the stadium but were turned away by stewards.
They then detonated explosive belts in the hope of causing a mass panic among the some 80,000 spectators inside the ground, French media reported.
"If we now put Euro 2016 in doubt we will be bowing to the rules of the terrorists," Lambert said.
Germany's Olympic Sports Association (DOSB) chief Alfons Hoermann agrees it would be wrong to call off the tournament or make hasty decisions.
"Whoever believes such an attack could not happen elsewhere is mistaken. Europe, the world, must stay together and take up the fight, as French President (Francois) Hollande has said," he told Germany's Frankfurter Allgemeine Sonntagszeitung.
Security has been the top priority for French organizers since the nation won the hosting rights in May 2010.
The attack in January on the editorial offices of the satirical magazine Charlie Hebdo demonstrated that terrorism was no longer merely a theoretical risk, and prompted widespread security reviews.
French Football Federation President Noel Le Graet said immediately after Friday's attacks: "Many precautionary measures have been taken but we have to see that terrorists can attack any time. We had concerns about the European Championship, now the concerns are greater."
France, which hosted the 1998 World Cup, is experienced in dealing with major sporting events including annual events such as the French Open tennis tournament in Paris or the Tour de France.
Security around Euro 2016 stadiums will probably be the smallest worry for organizers but experts say it will be difficult to secure bars and restaurants, transport and public events and festivities around matches.
"There is no 100 percent security," Helmut Spahn, who was security chief for the 2006 World Cup in Germany, told Germany's ZDF broadcaster. However he says it is possible "to minimize the risks."
Spahn says the French crisis management around the stadium Friday was generally good, however in a Welt am Sonntag interview he did question why stadium announcements were only in French.
It will be important for the French organizers to share and coordinate knowledge from European counterparts, as German security officials did in 2006, he said.
In four weeks, Paris will get a taste of Euro 2016 when the tournament draw takes place on Dec. 12 at Le Palais de Congres de Paris in the west of the city.
Germany's coach Joachim Loew and team manager Oliver Bierhoff, who is set to take part in the draw, will return to Paris with an uneasy feeling after spending the night with the German team in the Stade de France following the game against France.
Italy coach Antonio Conte probably spoke for many when he spoke of his fears ahead of Euro 2016. "It's worrying, there is no doubt. It is a very scary situation," he said.