Both nation-state and non-nation-state organized groups have attacked the US since the invention of nuclear weapons. (On US territory itself—notably on 9/11/2001—but more often US military assets off US territory, which is the closest equivalent to attacking a GPS satellite.)
We can't just start blowing up satellites in stable orbits.
>To spend billions to prepare for extremely unlikely event does not seem to be very rational thing to do.
Nuclear weapons were not free to develop.
I just don't see what to invest in for a Space Force. Anyone looking to attack something like GPS would either use something like ground base lasers, software/network hacks, or traditional projectiles. Anything developed by the US would either be obsolete by the time its needed or get sold to adversaries and used right back at us.
Outside of defense I know a large military and weapons help in having influence, but so does having a stable and large economy--the later moreso.
Nuclear weapons were developed out of a competition for survival. The people involved knew even in the hands of the Allied forces it was extremely dangerous. You're arguing we should invest in a Space Force because someone else might do it in the future.
It is extremely unlikely that someone will start knocking down US satellites, that would be an equivalent of attacking US, that never happened after invention of nuclear weapons. To spend billions to prepare for extremely unlikely event does not seem to be very rational thing to do. Meanwhile there are serious problems facing country and humanity in general global worming, automation takes away millions of jobs, opioid crisis, millions of people without health insurance, school system that has major issues.
>> Everyone's favorite rational pop scientist, Neil deGrasse Tyson, thinks it's "not a weird idea."
Yes, Neil gets exited when space gets any attention.