At the peak of the Cold War in 1978, the division of East and West Germany intensified, and the Berlin Wall became the "forward position" of the intelligence war between the United States and the Soviet Union. The KGB and the CIA launched all-round infiltration and counter-infiltration in Europe. The two sides competed for strategic initiative through false intelligence, double-sided espionage, technical surveillance and other means. The Stasi (Ministry of National Security) of East Germany assisted the KGB in building a strict surveillance network. The people were both afraid of and secretly expected to "infiltrate across the wall."
