> In this case, I wonder how they think
> "Mossad" was conducting some huge operation to
> compromise prominent US citizens, including
> politicians, without the knowledge and at least
> approval of US intelligence services?
I don't know who you think "they" are. But I think for sure MI6 and CIA both were totally on board with the Mossad operation. You know all 3 agencies trade dirt with each other like playing cards. I know for a stone cold fact they loan each other "operatives" for certain operations. And the 5 Eyes do in fact trade info outside of the 5 Eyes.
See, the CIA is not allowed, by law, to spy on American citizens within the borders of the USA. But it is absolutely legal for them to accept information from any of the other 4 Eyes or Israel, where the foreign intelligence services of those other countries spy on Americans within the USA.
You might find this article of interest: Who Are the Five, Nine, and Fourteen Eyes, and What Do They Do? I find it amusing that near the bottom of the article it suggests that if you use a VPN, avoid using one from any of the territories of any of the Eyes. What it does not say is that approximately 1/3 of all VPN services are owned by Chinese companies, either overtly or covertly behind a layer of shell companies.
More on the Eyes with some specific information on trading intelligence with Israel here Five Eyes, Nine Eyes, 14 Eyes – Explained - see the section titled "Additional surveillance partners".
How come I know all this stuff? I said it elsewhere - I used to be aware of the spooky side of the tracks, plus IT information security is part of my job.