The Paris Olympics begin this Friday, and France is contending with what security experts have described as the most volatile geopolitical environment in decades.

Among the worries keeping the French government up at night are the looming threats of nuclear conflict with Russia, potential sabotage by foreign agents, the war in the Middle East, widespread protests and terrorism plots.

Meanwhile, blocking cyber attacks on the Games has almost become an Olympic sport in itself. 

Today, crime reporter Marta Pascual Juanola on what security measures are in place, to keep civilians and athletes alike, safe. And whether tension at the games could spill over into a wider European conflict.