The US has snooped on Israel for years there was the incident involving the USS Liberty back in 1967.
My uncle was a snoop in the Air Force and he spent a tour at the post in Brindisi, Italy. I know that he snooped on Arab and Soviet networks but he has described to me an incident involving IDAF fighters and Egyptian fighters. The Egyptians got confused and one pilot flew into the ground not a good day for the Egyptian air force this would have been some time between 1971 and 1974. As you might assume clearly another American was translating what the IDAF was saying while my uncle translated the Egyptians.
I wonder what he is legally bound not mention but you can sure it must be very interesting if you observe the dates he was snooping in the region (Yom Kipur War).
Im certain in his life time and probably mine as well some things will remain classified that he might have been privy to.