In The Drumhead on TNG, Admiral Norah Satie was depicted as a paranoid fanatic who saw phantom conspiracies everywhere. Among other things she was convinced that Simon Tarses was a Romulan spy, she believed the old slander that Worf’s father conspired with the Romulans, and she is concerned about the Romulan spy who was on board the Enterprise in the Data’s Day episode.

The Drumhead wants us to believe that’s out of her mind, and she ends up being disgraced within Starfleet, but the events of PIC show that she was right all along. There are Romulan moles within Starfleet - and there always were.

First of all she was right to suspect Tarses. He claimed he was one-quarter Vulcan, but he was actually one-quarter Romulan. He was in fact compromised by the Romulans and was not simply an innocent medical technician, but a spy on the Enterprise. He was working with a fellow spy, the Klingon J’Dan, passing on to the Romulans classified information about the Enterprise’s dilithium articulation frame. Or at least, that was the information that was discovered during the investigation in The Drumhead. What else was he passing along?

Since we now know that the Romulans are extremely interested in synths, Tarses must have also collecting about Data. Most significantly, we learn in The Drumhead that Tarses’ family was from the Mars colony. His brother still lived there at the time. Surely this can’t be a coincidence! Was his brother also compromised by the Romulans, passing them information about the Utopia Planitia shipyards?

The Romulans on PIC are also interested in Borg technology for some reason. Satie was also suspicious of Picard’s time with the Borg, and she didn’t mention it out of random paranoia. She could see that Tarses was there to collect information on Picard and the Borg as well.

As for Data, this wasn’t his only encounter with a Romulan spy. In Data’s Day he recorded the events of a typical day for Bruce Maddox. On that very same day, the Enterprise was transporting the Vulcan ambassador T’Pel. T’Pel even interacted with Data privately and tried to get him to reveal information about the Enterprise’s deflector shields, which she passes off as a test when Data refuses. Of course it turns out that T’Pel is a Romulan spy, Selok. (So in this case, she is actually explicitly a spy on-screen, we don't even need to theorize!) What exactly were the Romulans looking for in this episode? It’s not clear but obviously they were quite interested in how Data operates.

Admiral Satie mentioned his incident as well during The Drumhead, and again, not because she was a paranoid lunatic. She knew that Starfleet was already succumbing to Romulan infiltration.

And now in PIC, Commodore Oh and Rizzo/Narissa are Romulans masquerading as Vulcans in Starfleet. Oh has even reached the rank of Commodore without anyone ever noticing.

This infiltration probably goes back much further - all the way back to Valeris on the Enterprise-A. As far as we know, she was a Vulcan who was simply conspiring with the Romulan ambassador Nanclus, but maybe she too, like Selok, Oh, and Narissa, was actually a Romulan all along. After all, she was the one who suggested serving Romulan ale…