I will say again, the talk of an actual killswitch is overstated. The US does not need to place a system into the F-16 in order to disable it. Now we are talking in technology about the "Internet of things", different objects communicating with each other. It is very easy for those who made the Link 16 system to access it... And by doing so they can insert a virus or command line that will lead to a catastrophic failure of the wholde system (disabling the radar, FCS, ecm, communications, gps, fuel systems, the actual jet engine, ect.). We have seen in when a Chinese research team hacked a tesla model s to take over its brakes and other critical systems from 12 miles away.
https://www.google.com/amp/s/www.wa...hack-tesla-model-s/?client=ms-android-verizon
We also saw it in Iran when US/Israeli intelligence agencies attacked an Iranian Nuclear facility at Natanz and destroyed 1/5th of Irans centrifuges using the Stuxnet virus. If you dont think the people who created Link 16 can use it to access critical F-16 systems (and have already done it in 2008 to the Israelis, granted without destroying the systems, just to spy on it) but were able to attack an Iranian Nuclear installation and destroy 1/5 of that country's centrifuges, if you think they can't do the same to the F-16 you are living in a dream world.
All this is not to say that the US would actually carry out such an attack, I dont believe it would unless the US and Pakistan find themselves in open conflict with one another (which again is highly unlikely). I certainly dont think they would do so on behalf of India (it would complicate our efforts tremendously in Afghanistan) and any Indian living in the delusion that we would just needs to see our treatment of Pakistan in 71. We operate for our interests, you operate for yours. And it is not in US interest to take sides in an armed conflict that could draw us and China in to conflict as well.