[@VitaVitaAR]

1. Again, that is still not the entire world, and likely anyone that got involved would have to go through an immense debrief process. This is still around a maximum of 1 million more people knowing compared to 6 billion. The Difference is massive. The reason the cover up had to happen was to preserve magus society because once you blow the lid on that, 95% of the world wants your neck.

2. Fate Requieum has a unique plot hook that makes it plausible which is [i]Everybody has a grail[/i] meaning everyone has a constant source of mystery right near them. Which would offset the knowledge of servants and magic. This doesn't appear to be the case here so the reqieum explanation doesn't exactly work.


3. Nukes can't fire themselves as you say, but servants can. And a single nuke doesn't annilhilate the entire world. But Gil can. The difference between these two things are too great. And a reminder. Mutually assured destruction only works when everyone has nukes. Not everyone has servants in this case so yes. This woudl cause riots since fusang is the only place with these super humans. 

People don't live in fear of nukes because [i]everyone[/i] has them, not everyone has a Gilgamesh for instance.

4. Fusang is still a security risk to many nations wellbeing, due to what it is and the servant calibur. Someone could summon Karna. What are you going to do to a man whom is invulnerable to 95% of all harm. Shoot him? Theres also ethnic issues with servants but thats beside the point.

5.
Fusang itself is a huge geopolitcal issue because if this is the only place that has these things called servants. How on earth are we gonna defend our selfs (says country X not currently in the united nation)

This is how you start a millitary arms race.