I'm not a gamblin' man but I'm willing to stake good money on Humankind's ingenuity prevailing over the next 798 years.
These things happen far more than people realize, meteors explode in the atmosphere on a regular basis.
If you are not familiar with the Tunguska blast in 1908 you should realize that such an event would wipe out any major metropolitan area. And it would be assumed that it was a nuclear blast.
The evidence would not bear this out, but by then it would most likely be too late, some sort of retaliation would have taken place.
Unless you believe that a politician could resist the enormous pressure to retaliate. Who is retaliated against wouldn't be a matter of prime importance.