History of Germany (1945–90) eventually hundreds of thousands of people in several cities—particularly in Leipzig—continued to grow. On 7 October, the Soviet leader Mikhail Gorbachev visited Berlin to celebrate the 40th anniversary of the establishment of East Germany and urged the East German leadership to pursue reform, without success. The movement of civil resistance against the East German regime—both the emigration and the demonstrations—continued unabated. On 18 October, Erich Honecker was forced to resign as head of the SED and as head of state and was replaced by Egon Krenz. But the exodus continued unabated, and pressure for political reform mounted. On 4 November,
Peaceful Revolution had seen the Warsaw Pact invade Czechoslovakia in 1968 to quell the Prague Spring liberal reforms was replaced by the so-called Sinatra Doctrine; this policy announcement was in fact retrospective as the Soviet Union had already failed to militarily intervene – despite urging from the GDR leader Erich Honecker – during the Polish crisis of 1980–81. Gorbachev's decision largely stemmed from the lack of economic development within the Eastern Bloc in comparison to the western industrial nations due to the persistence of increasingly incompatible production structures and the failure to create service-orientated, micro-electronic or globalized industries. The Soviet Union therefore