This has nothing to do with saving hundreds of thousands of lives, get real pal. This is because of the billions of dollars in advertising, marketing, and swag associated with the event. The biggest advertisers in the world have spent tens of millions just getting ready for it.
If there was a terrorist attack during the event, it would hurt the economy very deeply for years to come as people avoided the event.
Additionally it isn't a few tens of millions, the Iraq war is already in the trillions, we have scanners that cost hundreds of millions, the shredding of our founding document, the list goes on and on. All in the name of fighting terrorism to hide the failed foreign policy of the past 60 years.
A few tens of million.... that's some funny fucking shit right there.