On the water, perched on rooftops and operating AI-augmented cameras, French security forces will lock down central Paris during the opening ceremony of the Olympics on July 26 aiming to prevent an incident that would ruin the biggest show on earth. The figures tell only part of the story of the colossal effort made to protect the river parade along the Seine, the first time a Summer Olympics has started outside a stadium. About 45,000 police and paramilitary officers will be on duty, along with 10,000 soldiers and 20,000 private security guards.

The total area that needs securing measures more than six kilometres (four miles) along the Seine and will contain around 300,000 ticketed spectators, as well as hundreds of thousands of other residents and tourists in overlooking buildings. A no-fly zone 150 kilometres wide around Paris will be enforced an hour before the ceremony starts at 7:30 p.m.

(1730 GMT), grounding or diverting all aviation at one of Europe's busiest airport hubs. "This opening ceremony is the most extraordinary thing a country can do," Interior Minister Gerald Darmanin told BFM television on July 24, adding: "As you know, in the current context of geopolitics and terrorism, it's an enormous challenge." The amount of specialised equipment and personnel illustrates the difficulty of securing such a risky environment— an open-air site with fast-flowing water, overlooked by hundreds of buildings.

All at a time when France is on its maximum alert for terror att.