First of, any war between India and Pakistan is unlikely to go beyond 10 days to two weeks at the max. We will be able to fly all our assets for the duration. The sanctions will impact the serviceability after the fact, but wont have any impact on the war itself.
Its also easy for people to criticize with the benefit of hindsight. You can bet your bottom dollar, had it been Pakistan that had caught and handed over OBL, our relationship with the US would be at a completely different level. Lets also not forget, the F-16s were ordered in 2006, and is still our most capable fighter. And the Block 3 is going to be coming circa 2021, that is 15 years after we ordered the new F-16s. That is a long time gap to be without a high end fighter. 18 F-16s for under $1.5B, 60 MLU kits for another $1.3B only is still an awesome bang for the buck. Cost might not be the only thing but its a huge part of it for a broke country.
https://www.defenseindustrydaily.co...es-upgrades-weapons-for-pakistans-f16s-02396/
Another thing to keep in mind is we have no other precision strike aircraft bar the F-16s until just last year when we placed an order for targeting pods for the JF-17. We are also not under any sanctions, and our relationship with the US has its eb and flows. Most likely in the next decade we will be upgrading our Block 52s to the Block 70 standard and that bird will be in PAF colors till 2040. So learn to live with it as theres a long way to go.
Btw, has the PAF set up any overhaul facilities for the RD-93 at Kamra yet? There were talks about it in 2015-2016 but havent read anything concrete since then. Thus in the time of war, its not just the F-16s we have to worry about but we are also dependent on the Russians for the engines for our most numerical fighter.