Stella Rimington joined the Britain’s MI5 in 1965 and during her thirty-year career worked in all the main fields of the Service’s responsibilities—countersubversion, counterespionage, and counterterrorism—and became successively Director of all three branches. Appointed Director-General of MI5 in 1992, she was the first woman to hold the post and the first Director-General whose name was publicly announced upon appointment. Stella Rimington is the author of At Risk, Secret Asset, and Illegal Action. She lives in London.

The Russian spy ring exposed this week in the U.S. was probably a serious operation, says former head of Britain’s intelligence agency MI5 Stella Rimington, as she shares stories of other famous networks of illegals.