Geoffrey Watkins appears in Patriot Games. He is the liason between the British Foreign Office and the Royal family. He also spies for the Ulster Liberation Army (ULA). When the ULA is destroyed, Watkins commits suicide by blowing his brains out.
Background
Geoffrey Watkins background is not much discussed, but it is revealed that he went to college at Winchester. Later he served in Belfast as a subaltern in 1969. He lost four men from his platoon during his time there, which led him to believe that England was doing the wrong thing in the wrong place, and losing men in the process. It is probable that this is where he met Dennis Cooley, who introduced him to Kevin O'Donnell.
Watkins eventually became the liason between the British Foreign Office and the Royal Family, gaining him access to some of the most closely-guarded secrets. Only O'Donnell, Sean Miller, and Cooley know of his allegiance to their cause. He provided the information for the attack on the Prince of Wales and his family.
Character
Watkins is described as being an inch shorter than Jack Ryan, with black hair that is turning grey. He is nearly forty, has pale skin, and blue eyes. Ryan notes that he looks like a diplomat and has a smile "so perfect that he must have practiced it in front of a mirror. It was the sort of smile that could have meant anything. Or more likely, nothing."
We are told that "Watkins loved games. All sorts." He collects books and plays tennis. Though modest and retiring, he is sharp and intelligent, noting that Ryan is talking with the head of the SIS at the dinner. He tends to deliberately provoke people to gauge their reactions, which causes Ryan to dislike him shortly after meeting him.
Patriot Games
Ryan is introduced to Watkins just before dinner at Buckingham Palace. Ryan soon decides he dislikes him, due to his habit of provoking people to see how they will react.
It is revealed shortly later that Watkins is the mole providing highly classified information to the ULA, via Cooley's book shop. He provides the intel that allows the ULA to rescue Miller from the prison transport. This leads the Scotland Yard to watch him, as one of the few people who knew both of the Prince of Wale's trip and of Sean Miller's transfer. When he later also sends along the royal family's itinerary for their summer trip to America, Scotland Yard notices. David Ashley soon learns that Cooley takes frequent trips to Ireland, which causes him and James Owens to suspect Watkins almost exclusively.
When Cooley learns his office is being bugged, Watkins receives a warning that their pipeline has been compromised, and that it is not known whether he is revealed. When O'Donnell and Miller are captured in America, he commits suicide in his office, even though Owens comments that they didn't have a scrap of usable evidence against him.