The stakes were raised. No longer were they debating open-plan offices or the employment of women in the civil service; now they dealt with nuclear deterrents, foreign policy, and international summits. Yet, the mechanics remained the same. In the episode "The Grand Design," Hacker attempts to assert his authority over nuclear defense, only to be manipulated into a position where he must keep the very weapons he intended to scrap. The show posited that even the most powerful person in the country is a prisoner of the system they pretend to run.
His efforts are systematically undermined by Sir Humphrey Appleby , the Permanent Secretary (and later Cabinet Secretary), who believes the role of the Civil Service is to ensure "stability" by preventing any actual change from occurring. Yes Minister And Yes Prime Minister