So, we spy on them too in a weird, incestuous, mutually-distrustful, but politically-useful relationship.

"Stepped-up NSA eavesdropping revealed to the White House how Mr. Netanyahu and his advisers had leaked details of the U.S.-Iran negotiations—learned through Israeli spying operations—to undermine the talks; coordinated talking points with Jewish-American groups against the deal; and asked undecided lawmakers what it would take to win their votes, according to current and former officials familiar with the intercepts."

https://www.wsj.com/articles/u-s-spy-net-on-israel-snares-co...

I think Israel just uses more HUMINT than SIGINT to do it, so we're occasionally able to snag one of their spies.