Kohl invited the GDR leader Honecker to the FRG, they agreed on some environmental and scientific issues.
The USSR was in bad economic circumstances, Honecker refused to accept Gorbachev's reforms and his economic restructuring.
Honecker was forced out in 1989, and the Berlin Wall was opened. The fall of the wall sent the country into chaos. Transport networks were thrown into turmoil and refugees flooded the west, using the already stretched welfare system.
Kohl seized the opportunity and went ahead with his ten point plan which included:
common institutions to be set up
bringing the GDR into the EEC
immediate medical assistance and foreign currency for travel
He had support from the CDU in his Bundestag. He was accused of being too hasty by his left-wing opponents, the USSR, the GDR and Thatcher
Kohl found an ally in the USA. Many were anxious about a strong unified Germany. Eventually, Brandt, SPD leader moved to support it, then the GDR and then the USSR.
Kohl promised the French a commitment to European integration and sent economic aid to the USSR to win over Gorbachev.
Kohl gave the CDU support in the GDR elections, he mounted a fierce campaign against a socialist vote. He promised the east instant prosperity, winning audiences of tens of thousands. The alliance had an overwhelming success with 48.1% of the vote.