Exactly. For this same reason, India recently deployed its own satellite navigation system NAVIC[1][2].
[1] https://en.wikipedia.org/wiki/Indian_Regional_Navigation_Sat...
http://timesofindia.indiatimes.com/home/science/How-Kargil-s...
Yet US sides with dictatorship which doesn't even control its own secret service which creates its own terrorist organizations (laskar-e-taeba).
Also, India did invade and annex Goa in '62.
... because Goa is an historically Indian territory, and Republic of India just got it back from foreign invaders!?
India "attacked" East Pakistan in the Bangladesh Liberation War [1]. Whether or not you or I feel it was justified is besides the point: it violated the sovereignty of another nation (similar to the U.S. in Iraq and Russia in Crimea).
[1] https://en.wikipedia.org/w/index.php?title=Bangladesh_Libera...
"India joined the war on 3 December 1971, after Pakistan launched preemptive air strikes on North India."
which doesn't sound out of the blue to me.
There is an enhanced footprint signal boost capability for the military but that's the opposite of what you describe.
The military has airborne and surface-based electronic warfare platforms that can be used to jam GPS. That's what is referenced on that page.
The FAA is not considered an authority for GPS, with the exception of certifying that WAAS is in-service for aircraft when it is meeting FAA specifications. For civilian information purposes the appropriate agency is the US Coast Guard NAVCEN.
The Air Force Space Command is the holds primary developmental, specification, and operational responsibility.
But I've searched around and can't find anything that indicates that this is a feature of the satellites themselves, rather it's just as you say, the US military has replaced SA with the general ability to jam local radio traffic, including GPS. E.g. [1] is another source for that.
So it does look like the US can't block GPS for entire countries anymore, I take that back.
I must say though, I think any public commentary about GPS capabilities should be taken with a huge grain of salt. It's a military system, they're very likely lying or not telling the full truth about what it's really capable of. E.g. I find the claim that the new generation can't do SA by design dubious, surely just fuzzing the signal by some offset is a rather trivial change.
1. https://web.archive.org/web/20050921115614/http://ngs.woc.no...
[1] http://www.dote.osd.mil/pub/reports/fy2011/pdf/af/2011gps.pd...
Each of those satellites in view would have to be implementing this scheme you suggest in order for it to be effective.
Since the satellites only have a single transmitter for each signal their entire receiving area would be affected by whatever modifications are made to implement SA. This means that to turn SA on for a single area more than half the globe would be getting a degraded signal from 1 or more satellites, which ones being undetectable.
I'm afraid SA is an all-or-nothing idea. Area denial (jamming) by surface and airborne transmitters is a much more workable approach. One could imagine jamming from space, but not using the GPS satellite vehicles.
So, to GPS. In the original GPS SA it is certainly true that many satellites would have to be using degraded mode to guarantee degradation for a specific point. However, the newer satellites have an additional directional antenna. While primarily for transmitting M-code to a specific region, it could equally be used for transmitting a self-jamming signal.
[1] https://en.wikipedia.org/wiki/Galileo_(satellite_navigation)...
Now now, do not insert political commentary into this discussions. I got yelled at for doing that. [1]
EDIT: to wit, the institution is the most powerful military force, active across the globe https://en.wikipedia.org/wiki/List_of_wars_involving_the_Uni...
It seems perfectly fair and reasonable reason to mention the power the president has in the situation given some of the president elect's statements.
It's strategically foolish for the major economies like the EU, Russia & China to depend on the US's goodwill in maintaining a system that drives a huge part of their economy, GPS is used pervasively for everything, and that's only increasing.
Trump wants NATO countries to pay their fair share, how long until he gets the idea that all countries around the world should pay a GPS licensing fee least GPS regional denial be turned on?
Those are the sort of reasons for why it makes sense to develop a GPS alternative, even if you're only aiming for feature parity, or even less than that.
1. https://www.faa.gov/about/office_org/headquarters_offices/at...