A further period of training followed from 1967 till 1969 at the Soviet Diplomatic Academy, leading to a doctorate. Dr. Krolikowski then served as his country's ambassador to Czechoslovakia in succession to Peter Florin and in the aftermath of the 1968 Warsaw Pact invasion of that country. He held this important diplomatic appointment from August 1969 till October 1973. At the eighth Party Congress in June 1971, Herbert Krolikowski's was one of the 54 names on the candidate list for membership of the SED Central Committee, and in May 1976, at the ninth party congress, he became one of the (by now) 145 Central Committee members. He retained his Central Committee membership till the mass resignation of the party Central Committee in December 1989, which took place in the context of the events leading to Germany reunification in October 1990. In terms of government positions, he was reappointed Deputy Foreign minister in November 1973, following his return from the Prague job, and in January 1975 became Secretary of State and First Minister for Foreign affairs - effectively deputy Foreign Minister - in succession to Oskar Fischer (who now headed up the foreign ministry). Krolikowski and Fischer both remained in post until 1990 and the final chapter in the forty-year existence of the German Democratic Republic.