I remember reading of the Israeli's helping the Indian Air Force upgrade. Among other things, they took the Mig-21, and gave it permanent external jammers, and renamed it the Buffalo(?). In any case, while the Mig-21 did not become stealth, it made locking on almost impossible, thus all fighting had to be done ACM.
In fact, Israel is going full non-stealth. Yes, they are buying some F-35s, though basically, the US is giving them foreign aide, which they in turn use to buy some F-35s. Translation, We The People are buying Israel some F-35s, and I suspect it is solely for the reason stated here: "Gee, the F-35 is so awesome even the Israelis are buying them!" It's like giving an NBA player a free pair of shoes to tell everyone, that NBA player loves my product!
The US would do well to dump the F-35, maybe even the F-22 and put all of that money back into F-15s and -16s. From a practical point of view, there isn't anything flying in the world, now or 20 years from now, that we can't dominate with upgraded Eagles and Vipers.
boo